Fixed a minor issue with markdown in the readme.txt.

git-svn-id: https://plugins.svn.wordpress.org/rt-hide-posts-page-editor/trunk@1004925 b8457f37-d9ea-0310-8a92-e5e31aec5664
Added proper CC licensing info for the "edit" icon used in the plugin's promotional artwork.

git-svn-id: https://plugins.svn.wordpress.org/rt-hide-posts-page-editor/trunk@1004929 b8457f37-d9ea-0310-8a92-e5e31aec5664