[doc] added docusaurus-based version control (#2656)

docs/sidebars.js

+module.exports = {
+  docs: [
+    {
+      type: 'category',
+      label: 'Get started',
+      collapsed: false,
+      items: [
+        'get_started/installation', 'get_started/run_demo',
+        'get_started/reading_roadmap'
+      ],
+    },
+    {
+      type: 'category',
+      label: 'Concepts',
+      collapsed: false,
+      items: [
+        'concepts/distributed_training', 'concepts/paradigms_of_parallelism',
+        'concepts/colossalai_overview'
+      ],
+    },
+    {
+      type: 'category',
+      label: 'Basics',
+      collapsed: false,
+      items: [
+        'basics/command_line_tool',
+        'basics/define_your_config',
+        'basics/launch_colossalai',
+        'basics/initialize_features',
+        'basics/engine_trainer',
+        'basics/configure_parallelization',
+        'basics/model_checkpoint',
+        'basics/colotensor_concept',
+      ],
+    },
+    {
+      type: 'category',
+      label: 'Features',
+      collapsed: false,
+      items: [
+        'features/mixed_precision_training', 'features/gradient_accumulation',
+        'features/gradient_clipping', 'features/gradient_handler',
+        'features/zero_with_chunk', {
+          type: 'category',
+          label: 'Tensor Parallel',
+          collapsed: true,
+          items: [
+            'features/1D_tensor_parallel',
+            'features/2D_tensor_parallel',
+            'features/2p5D_tensor_parallel',
+            'features/3D_tensor_parallel',
+          ],
+        },
+        'features/pipeline_parallel', 'features/nvme_offload'
+      ],
+    },
+    {
+      type: 'category',
+      label: 'Advanced Tutorials',
+      collapsed: false,
+      items: [
+        'advanced_tutorials/train_vit_using_pipeline_parallelism',
+        'advanced_tutorials/train_vit_with_hybrid_parallelism',
+        'advanced_tutorials/train_gpt_using_hybrid_parallelism',
+        'advanced_tutorials/define_your_own_parallel_model',
+        'advanced_tutorials/add_your_parallel',
+        'advanced_tutorials/meet_gemini',
+        'advanced_tutorials/parallelize_your_training_like_Megatron',
+        'advanced_tutorials/integrate_mixture_of_experts_into_your_model'
+      ],
+    },
+  ]
+};

docs/versions.json

+[
+  "current"
+]