[CI/Build] Fix pre-commit failure in docs (#21897)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

docs/design/fused_moe_modular_kernel.md

 # Fused MoE Modular Kernel
 
 ## Introduction
+
 FusedMoEModularKernel is implemented [here](gh-file:/vllm/model_executor/layers/fused_moe/modular_kernel.py)
 
 Based on the format of the input activations, FusedMoE implementations are broadly classified into 2 types.
@@ -31,7 +32,8 @@ As can be seen from the diagrams, there are a lot of operations and there can be
 
 The rest of the document will focus on the Contiguous / Non-Batched case. Extrapolating to the Batched case should be straight-forward.
 
-## ModularKernel Components:
+## ModularKernel Components
+
 FusedMoEModularKernel splits the FusedMoE operation into 3 parts,
 
 1. TopKWeightAndReduce
@@ -39,6 +41,7 @@ FusedMoEModularKernel splits the FusedMoE operation into 3 parts,
 3. FusedMoEPermuteExpertsUnpermute
 
 ### TopKWeightAndReduce
+
 The TopK Weight Application and Reduction components happen right after the Unpermute operation and before the All2All Combine. Note that the `FusedMoEPermuteExpertsUnpermute` is responsible for the Unpermute and `FusedMoEPrepareAndFinalize` is responsible for the All2All Combine. There is value in doing the TopK Weight Application and Reduction in the `FusedMoEPermuteExpertsUnpermute`. But some implementations choose to do it `FusedMoEPrepareAndFinalize`. In order to enable this flexibility, we have a TopKWeightAndReduce abstract class.
 
 Please find the implementations of TopKWeightAndReduce [here](gh-file:vllm/model_executor/layers/fused_moe/topk_weight_and_reduce.py).
@@ -50,12 +53,14 @@ The `FusedMoEModularKernel` acts as a bridge between the `FusedMoEPermuteExperts
 * `FusedMoEPermuteExpertsUnpermute::finalize_weight_and_reduce_impl` method returns `TopKWeightAndReduceContiguous` / `TopKWeightAndReduceNaiveBatched` / `TopKWeightAndReduceDelegate` if the `FusedMoEPermuteExpertsUnpermute` implementation needs the `FusedMoEPrepareAndFinalize::finalize()` to do the weight application and reduction.
 
 ### FusedMoEPrepareAndFinalize
+
 The `FusedMoEPrepareAndFinalize` abstract class exposes `prepare` and `finalize` functions.
 The `prepare` function is responsible for input activation Quantization and All2All Dispatch. The `finalize` function is responsible for invoking the All2All Combine. Additionally the `finalize` function may or may not do the TopK weight application and reduction (Please refer to the TopKWeightAndReduce section)
 
 ![](../assets/design/fused_moe_modular_kernel/prepare_and_finalize_blocks.png "FusedMoEPrepareAndFinalize Blocks")
 
 ### FusedMoEPermuteExpertsUnpermute
+
 The `FusedMoEPermuteExpertsUnpermute` class is where the crux of the MoE operations happen. The `FusedMoEPermuteExpertsUnpermute` abstract class exposes a few important functions,
 
 * apply()
@@ -63,6 +68,7 @@ The `FusedMoEPermuteExpertsUnpermute` class is where the crux of the MoE operati
 * finalize_weight_and_reduce_impl()
 
 #### apply()
+
 The `apply` method is where the implementations perform
 
 * Permute
@@ -74,50 +80,56 @@ The `apply` method is where the implementations perform
 * Maybe TopK Weight Application + Reduction
 
 #### workspace_shapes()
+
 The core FusedMoE implementation performs a series of operations. It would be inefficient to create output memory for each of these operations separately. To that effect, implementations are required to declare 2 workspace shapes, the workspace datatype and the FusedMoE output shape as outputs of the workspace_shapes() method. This information is used to allocate the workspace tensors and the output tensor in `FusedMoEModularKernel::forward()` and passed on to the `FusedMoEPermuteExpertsUnpermute::apply()` method. The workspaces could then be used as intermediate buffers in the FusedMoE implementation.
 
 #### finalize_weight_and_reduce_impl()
+
 It is sometimes efficient to perform TopK weight application and Reduction inside the `FusedMoEPermuteExpertsUnpermute::apply()`. Find an example [here](https://github.com/vllm-project/vllm/pull/20228). We have a `TopKWeightAndReduce` abstract class to facilitate such implementations. Please refer to the TopKWeightAndReduce section.
 `FusedMoEPermuteExpertsUnpermute::finalize_weight_and_reduce_impl()` returns the `TopKWeightAndReduce` object that the implementation wants the `FusedMoEPrepareAndFinalize::finalize()` to use.
 
 ![](../assets/design/fused_moe_modular_kernel/fused_experts_blocks.png "FusedMoEPermuteExpertsUnpermute Blocks")
 
 ### FusedMoEModularKernel
+
 `FusedMoEModularKernel` is composed of the `FusedMoEPrepareAndFinalize` and `FusedMoEPermuteExpertsUnpermute` objects.
 `FusedMoEModularKernel` pseudocode/sketch,
 
-```
-FusedMoEModularKernel::__init__(self,
-            prepare_finalize: FusedMoEPrepareAndFinalize,
-            fused_experts: FusedMoEPermuteExpertsUnpermute):
+```py
+class FusedMoEModularKernel:
+    def __init__(self,
+                 prepare_finalize: FusedMoEPrepareAndFinalize,
+                 fused_experts: FusedMoEPermuteExpertsUnpermute):
+
+        self.prepare_finalize = prepare_finalize
+        self.fused_experts = fused_experts
 
-    self.prepare_finalize = prepare_finalize
-    self.fused_experts = fused_experts
+    def forward(self, DP_A):
 
-FusedMoEModularKernel::forward(self, DP_A):
+        Aq, A_scale, _, _, _ = self.prepare_finalize.prepare(DP_A, ...)
 
-    Aq, A_scale, _, _, _ = self.prepare_finalize.prepare(DP_A, ...)
+        workspace13_shape, workspace2_shape, _, _ = self.fused_experts.workspace_shapes(...)
 
-    workspace13_shape, workspace2_shape, _, _ = self.fused_experts.workspace_shapes(...)
+        # allocate workspaces
+        workspace_13 = torch.empty(workspace13_shape, ...)
+        workspace_2 = torch.empty(workspace2_shape, ...)
 
-    # allocate workspaces
-    workspace_13 = torch.empty(workspace13_shape, ...)
-    workspace_2 = torch.empty(workspace2_shape, ...)
+        # execute fused_experts
+        fe_out = self.fused_experts.apply(Aq, A_scale, workspace13, workspace2, ...)
 
-    # execute fused_experts
-    fe_out = self.fused_experts.apply(Aq, A_scale, workspace13, workspace2, ...)
+        # war_impl is an object of type TopKWeightAndReduceNoOp if the fused_experts implementations
+        # performs the TopK Weight Application and Reduction.
+        war_impl = self.fused_experts.finalize_weight_and_reduce_impl()
 
-    # war_impl is an object of type TopKWeightAndReduceNoOp if the fused_experts implementations performs the TopK Weight Application and Reduction.
-    war_impl = self.fused_experts.finalize_weight_and_reduce_impl()
+        output = self.prepare_finalize.finalize(fe_out, war_impl,...)
 
-    output = self.prepare_finalize.finalize(fe_out, war_impl,...)
-                            
-    return output
+        return output
 ```
 
 ## How-To
 
 ### How To Add a FusedMoEPrepareAndFinalize Type
+
 Typically a FusedMoEPrepareAndFinalize type is backed by an All2All Dispatch & Combine implementation / kernel. For example,
 
 * PplxPrepareAndFinalize type is backed by Pplx All2All kernels,
@@ -125,9 +137,11 @@ Typically a FusedMoEPrepareAndFinalize type is backed by an All2All Dispatch & C
 * DeepEPLLPrepareAndFinalize type is backed by DeepEP Low-Latency All2All kernels.
 
 #### Step 1: Add an All2All manager
+
 The purpose of the All2All Manager is to setup the All2All kernel implementations. The `FusedMoEPrepareAndFinalize` implementations typically fetch a kernel-implementation "handle" from the All2All Manager to invoke the Dispatch and Combine functions. Please look at the All2All Manager implementations [here](gh-file:vllm/distributed/device_communicators/all2all.py).
 
 #### Step 2: Add a FusedMoEPrepareAndFinalize Type
+
 This section describes the significance of the various functions exposed by the `FusedMoEPrepareAndFinalize` abstract class.
 
 `FusedMoEPrepareAndFinalize::prepare()`: The prepare method implements the Quantization and All2All Dispatch. Typically the Dispatch function from the relevant All2All Manager is invoked.
@@ -145,6 +159,7 @@ This section describes the significance of the various functions exposed by the
 We suggest picking an already existing `FusedMoEPrepareAndFinalize` implementation that matches your All2All implementation closely and using it as a reference.
 
 ### How To Add a FusedMoEPermuteExpertsUnpermute Type
+
 FusedMoEPermuteExpertsUnpermute performs the core of the FusedMoE operations. The various functions exposed by the abstract class and their significance is as follows,
 
 `FusedMoEPermuteExpertsUnpermute::activation_formats()`: Return the supported Input and Output activation formats. i.e. Contiguous / Batched format.
@@ -159,12 +174,14 @@ implementations that input `FusedMoEActivationFormat.Standard` support chunking
 `FusedMoEPermuteExpertsUnpermute::apply`: Refer to `FusedMoEPermuteExpertsUnpermute` section above.
 
 ### FusedMoEModularKernel Initialization
+
 `FusedMoEMethodBase` class has 2 methods that are collectively responsible in creating the `FusedMoEModularKernel` object. They are,
 
 * select_gemm_impl, and
 * init_prepare_finalize
 
 #### select_gemm_impl
+
 The `select_gemm_impl` method is undefined in the base class. It is the responsibility of the derived class to implement a method that constructs a valid/appropriate `FusedMoEPermuteExpertsUnpermute` object.
 Please refer to the implementations in,
 
@@ -176,12 +193,14 @@ Please refer to the implementations in,
 dervied classes.
 
 #### init_prepare_finalize
+
 Based on the input and env settings, the `init_prepare_finalize` method creates the appropriate `FusedMoEPrepareAndFinalize` object. The method then queries `select_gemm_impl` for the appropriate `FusedMoEPermuteExpertsUnpermute` object and builds the `FusedMoEModularKernel` object
 
 Please take a look at [init_prepare_finalize](https://github.com/vllm-project/vllm/blob/1cbf951ba272c230823b947631065b826409fa62/vllm/model_executor/layers/fused_moe/layer.py#L188).
 **Important**: The `FusedMoEMethodBase` derived classes use the `FusedMoEMethodBase::fused_experts` object in their `apply` methods. When settings permit the construction of a valid `FusedMoEModularKernel` object, we override `FusedMoEMethodBase::fused_experts` with it. This essentially makes the derived classes agnostic to what FusedMoE implementation is used.
 
 ### How To Unit Test
+
 We have `FusedMoEModularKernel` unit tests at [test_modular_kernel_combinations.py](gh-file:tests/kernels/moe/test_modular_kernel_combinations.py).
 
 The unit test iterates through all combinations of `FusedMoEPrepareAndFinalize` and `FusedMoEPremuteExpertsUnpermute` types and if they are
@@ -196,18 +215,21 @@ If you are adding some `FusedMoEPrepareAndFinalize` / `FusedMoEPermuteExpertsUnp
 Doing this will add the new implementation to the test suite.
 
 ### How To Check `FusedMoEPrepareAndFinalize` & `FusedMoEPermuteExpertsUnpermute` Compatibility
+
 The unit test file [test_modular_kernel_combinations.py](gh-file:tests/kernels/moe/test_modular_kernel_combinations.py) can also be executed as a standalone script.
 Example: `python3 -m tests.kernels.moe.test_modular_kernel_combinations --pf-type PplxPrepareAndFinalize --experts-type BatchedTritonExperts`
 As a side-effect, this script can be used to test `FusedMoEPrepareAndFinalize` & `FusedMoEPermuteExpertsUnpermute` compatibility. When invoked
 with incompatible types, the script will error.
 
 ### How To Profile
+
 Please take a look at [profile_modular_kernel.py](gh-file:tests/kernels/moe/modular_kernel_tools/profile_modular_kernel.py)
 The script can be used to generate Torch traces for a single `FusedMoEModularKernel::forward()` call for any compatible
 `FusedMoEPrepareAndFinalize` and `FusedMoEPermuteExpertsUnpermute` types.
 Example: `python3 -m tests.kernels.moe.modular_kernel_tools.profile_modular_kernel --pf-type PplxPrepareAndFinalize --experts-type BatchedTritonExperts`
 
 ## FusedMoEPrepareAndFinalize Implementations
+
 The following table lists the `FusedMoEPrepareAndFinalize` implementations at the time of writing,
 
 | Implementation | Type | Comments |
@@ -220,6 +242,7 @@ The following table lists the `FusedMoEPrepareAndFinalize` implementations at th
 | BatchedPrepareAndFinalize | Batched | A reference prepare/finalize class that reorganizes the tokens into expert batched format, i.e. E x max_num_tokens x K. (Doesn’t use any all2all kernels. This is primarily used in unit testing) |
 
 ## FusedMoEPermuteExpertsUnpermute
+
 The following table lists the `FusedMoEPermuteExpertsUnpermute` implementations at the time of writing,
 
 | Implementation | Type | Comment |