Custom Windows Pinned Tiles: Readme updates for 2.1.

git-svn-id: https://plugins.svn.wordpress.org/custom-windows-pinned-tiles/trunk@989737 b8457f37-d9ea-0310-8a92-e5e31aec5664
Custom Windows Pinned Tiles: version 2.1.

git-svn-id: https://plugins.svn.wordpress.org/custom-windows-pinned-tiles/trunk@989739 b8457f37-d9ea-0310-8a92-e5e31aec5664