Reorganize existing documentation files

This change creates two directories of content, based on who they're
relevant to: users and contributors. Files which were in the top-level
folder were moved, as well as some within folders in that top-level.
This is one change of a multi-step process, so it only deals with
renamings in order to make further changes cleaner.

Change-Id: I3c9bb7da4f283e2696e7bcea84824c778bbcecfb
Partial-Bug: 1416553

doc/source/index.rst

@@ -6,10 +6,10 @@ Welcome!
 .. toctree::
    :maxdepth: 2
 
-   installation
-   usage
-   contributing
-   glossary
+   users/installation
+   users/usage
+   contributors/contributing
+   users/glossary
 
 User Guides
 -----------
@@ -17,7 +17,7 @@ User Guides
 .. toctree::
    :maxdepth: 1
 
-   userguides/object_store
+   users/userguides/object_store
 
 High-Level Interface
 --------------------
@@ -25,7 +25,7 @@ High-Level Interface
 .. toctree::
    :maxdepth: 1
 
-   highlevel/object_store
+   users/highlevel/object_store
 
 Resource Level Classes
 ----------------------
@@ -33,8 +33,8 @@ Resource Level Classes
 .. toctree::
    :maxdepth: 1
 
-   resources/object_store/v1/container
-   resources/object_store/v1/obj
+   users/resources/object_store/v1/container
+   users/resources/object_store/v1/obj
 
 Low-Level Classes
 -----------------
@@ -42,13 +42,13 @@ Low-Level Classes
 .. toctree::
    :maxdepth: 1
 
-   connection
-   user_preference
-   session
-   transport
-   base_auth_plugin
-   identity_base
-   identity_v2
-   identity_v3
-   resource
-   service_filter
+   users/connection
+   users/user_preference
+   users/session
+   users/transport
+   users/base_auth_plugin
+   users/identity_base
+   users/identity_v2
+   users/identity_v3
+   users/resource
+   users/service_filter

doc/source/users/highlevel/object_store.rst

@@ -1,7 +1,7 @@
 Object Store API
 ================
 
-For details on how to use this API, see :doc:`/userguides/object_store`
+For details on how to use this API, see :doc:`/users/userguides/object_store`
 
 .. automodule:: openstack.object_store.v1._proxy