Adds .gitignore

git-svn-id: http://plugins.svn.wordpress.org/sketchfab-viewer/trunk@834649 b8457f37-d9ea-0310-8a92-e5e31aec5664
[Delivers #63407842] Updates admin menu title

git-svn-id: http://plugins.svn.wordpress.org/sketchfab-viewer/trunk@834650 b8457f37-d9ea-0310-8a92-e5e31aec5664
Merge branch 'master' of github.com:sketchfab/wordpress-plugin