update docs

docs/source/api/pgl.contrib.heter_graph.rst → docs/source/api/pgl.heter_graph.rst

-pgl.contrib.heter\_graph module: Heterogenous Graph Storage
+pgl.heter\_graph module: Heterogenous Graph Storage
 ===============================
 
-.. automodule:: pgl.contrib.heter_graph
+.. automodule:: pgl.heter_graph
    :members:
    :undoc-members:
    :show-inheritance:

docs/source/api/pgl.contrib.heter_graph_wrapper.rst → docs/source/api/pgl.heter_graph_wrapper.rst

-pgl.contrib.heter\_graph\_wrapper module: Heterogenous Graph data holders for Paddle GNN.
+pgl.heter\_graph\_wrapper module: Heterogenous Graph data holders for Paddle GNN.
 =========================
 
-.. automodule:: pgl.contrib.heter_graph_wrapper
+.. automodule:: pgl.heter_graph_wrapper
    :members:
    :undoc-members:
    :show-inheritance:

docs/source/api/pgl.rst

@@ -9,5 +9,5 @@ API Reference
    pgl.data_loader
    pgl.utils.paddle_helper
    pgl.utils.mp_reader
-   pgl.contrib.heter_graph
-   pgl.contrib.heter_graph_wrapper
+   pgl.heter_graph
+   pgl.heter_graph_wrapper