[doc] update rst and docstring (#1351)

* update rst

* add zero docstr

* fix docstr

* remove fx.tracer.meta_patch

* fix docstr

* fix docstr

* update fx rst

* fix fx docstr

* remove useless rst

docs/colossalai/colossalai.rst

@@ -1,18 +1,26 @@
 colossalai
 ==========
 
+.. automodule:: colossalai
+   :members:
+
 .. toctree::
    :maxdepth: 2
 
    colossalai.amp
    colossalai.builder
+   colossalai.cli
    colossalai.communication
    colossalai.context
    colossalai.engine
+   colossalai.fx
+   colossalai.gemini
    colossalai.kernel
    colossalai.logging
    colossalai.nn
+   colossalai.pipeline
    colossalai.registry
+   colossalai.tensor
    colossalai.testing
    colossalai.trainer
    colossalai.utils
@@ -22,4 +30,7 @@ colossalai
 .. toctree::
    :maxdepth: 2
 
+   colossalai.constants
+   colossalai.core
+   colossalai.global_variables
    colossalai.initialize