Docs changes according to Miratins review.

Added release notes in doc.
Added TCs: MOS8.0=>9.0 update, plugins minor version update.
Pictures with correct plugin version in docs.

Change-Id: Iad0cd60f19c43d06b816c2b43cd35c8019557c1d

doc/source/index.rst

@@ -8,6 +8,7 @@ Plugin Guide
 .. toctree::
    :maxdepth: 2
 
+   release_notes
    introduction
    installation
    guide

doc/source/release_notes.rst

@@ -0,0 +1,16 @@
+Release Notes v2.1.1
+====================
+
+
+New Features
+----------------
+
+1. Mirantis Fuel 9.0 support.
+2. RAM Cache (RMCache) support.
+3. Using special FronEnd ScaleIO user in Cinder and Nova to access ScaleIO cluster instead of the 'admin' user.
+4. Ability to keep Glance images on ScaleIO.
+
+Fixed Bugs
+----------------
+
+1. Fixed algorithm of protection domain auto-creation if number of SDS-es becomes larger than a threshold in the plugin settings.