Adapt watcher documentation for new standards

This patch set makes the following changes:

 * Add index file to each subdirectory of doc/source
 * Update doc/source/index.rst with new links
 * Move content of install-guide to the doc/source/install
 * Minor changes

Depends-On: Ifc5512c0e2373cf3387e0e0498268eab092e52bb
Change-Id: Iecb4f60efb015a56b9b37331859848b287112842

doc/source/install/index.rst

@@ -0,0 +1,39 @@
+===================================
+Infrastructure Optimization service
+===================================
+
+.. toctree::
+   :maxdepth: 2
+
+   get_started.rst
+   install.rst
+   verify.rst
+   next-steps.rst
+
+The Infrastructure Optimization service (watcher) provides
+flexible and scalable resource optimization service for
+multi-tenant OpenStack-based clouds.
+
+Watcher provides a complete optimization loop including
+everything from a metrics receiver, complex event processor
+and profiler, optimization processor and an action plan
+applier. This provides a robust framework to realize a wide
+range of cloud optimization goals, including the reduction
+of data center operating costs, increased system performance
+via intelligent virtual machine migration, increased energy
+efficiency—and more!
+
+Watcher also supports a pluggable architecture by which custom
+optimization algorithms, data metrics and data profilers can be
+developed and inserted into the Watcher framework.
+
+Check the documentation for watcher optimization strategies at
+https://docs.openstack.org/developer/watcher/strategies
+
+Check watcher glossary at
+https://docs.openstack.org/developer/watcher/glossary.html
+
+
+This chapter assumes a working setup of OpenStack following the
+`OpenStack Installation Tutorial
+<https://docs.openstack.org/project-install-guide/ocata/>`_.