Update toctree of neutron document

* Display more contents in the top page.
  It is useful to access various things from the top page.
  The contents after this change looks reasonable.
* Remove "Indices and tables" section in policies and stadium index.
  They are unnecessary.

Change-Id: I49a966ce96af107c6f17f4caa73f9a634db37e18

doc/source/index.rst

@@ -43,7 +43,7 @@ Neutron Policies
 ================
 
 .. toctree::
-   :maxdepth: 1
+   :maxdepth: 2
 
    policies/index
 
@@ -51,7 +51,7 @@ Neutron Stadium
 ===============
 
 .. toctree::
-   :maxdepth: 1
+   :maxdepth: 2
 
    stadium/index
 
@@ -59,7 +59,7 @@ Developer Docs
 ==============
 
 .. toctree::
-   :maxdepth: 1
+   :maxdepth: 3
 
    devref/index
 

doc/source/policies/index.rst

@@ -21,8 +21,6 @@ Neutron. This includes the processes we use for blueprints and specs, bugs,
 contributor onboarding, core reviewer memberships, and other procedural
 items.
 
-Policies
---------
 .. toctree::
    :maxdepth: 3
 
@@ -34,10 +32,3 @@ Policies
    code-reviews
    thirdparty-ci
    office-hours
-
-Indices and tables
-------------------
-
-* :ref:`genindex`
-* :ref:`modindex`
-* :ref:`search`

doc/source/stadium/index.rst

@@ -19,17 +19,8 @@ Neutron Stadium
 The Stadium Guide contains information on policies and procedures for the
 Neutron Stadium.
 
-Stadium
--------
 .. toctree::
    :maxdepth: 3
 
    sub_projects
    sub_project_guidelines
-
-Indices and tables
-------------------
-
-* :ref:`genindex`
-* :ref:`modindex`
-* :ref:`search`