[Doc and User Guide] Minor Fix (#2205)

* Fix doc and user guide

* Update heterograph.py
Co-authored-by: Ubuntu <ubuntu@ip-172-31-13-9.us-west-2.compute.internal>

docs/source/guide/training-graph.rst

@@ -210,9 +210,9 @@ DGL implements
 `GIN <https://github.com/dmlc/dgl/tree/master/examples/pytorch/gin>`__
 as an example of graph classification. The training loop is inside the
 function ``train`` in
-```main.py`` <https://github.com/dmlc/dgl/blob/master/examples/pytorch/gin/main.py>`__.
+`main.py <https://github.com/dmlc/dgl/blob/master/examples/pytorch/gin/main.py>`__.
 The model implementation is inside
-```gin.py`` <https://github.com/dmlc/dgl/blob/master/examples/pytorch/gin/gin.py>`__
+`gin.py <https://github.com/dmlc/dgl/blob/master/examples/pytorch/gin/gin.py>`__
 with more components such as using
 :class:`dgl.nn.pytorch.GINConv` (also available in MXNet and Tensorflow)
 as the graph convolution layer, batch normalization, etc.

python/dgl/dataloading/pytorch/__init__.py

@@ -240,8 +240,8 @@ class EdgeDataLoader:
     ----------
     g : DGLGraph
         The graph.
-    nids : Tensor or dict[ntype, Tensor]
-        The node set to compute outputs.
+    eids : Tensor or dict[etype, Tensor]
+        The edge set in graph :attr:`g` to compute outputs.
     block_sampler : dgl.dataloading.BlockSampler
         The neighborhood sampler.
     g_sampling : DGLGraph, optional

python/dgl/heterograph.py

@@ -2596,7 +2596,8 @@ class DGLHeteroGraph(object):
         Parameters
         ----------
         v : int
-            The node ID.
+            The node ID. If the graph has multiple edge types, the ID is for the destination
+            type corresponding to the edge type.
         etype : str or (str, str, str), optional
             The type names of the edges. The allowed type name formats are:
 
@@ -2654,7 +2655,8 @@ class DGLHeteroGraph(object):
         Parameters
         ----------
         v : int
-            The node ID.
+            The node ID. If the graph has multiple edge types, the ID is for the source
+            type corresponding to the edge type.
         etype : str or (str, str, str), optional
             The type names of the edges. The allowed type name formats are: