updated README
marketing images for Chrome Store
Merge branch 'master' of https://github.com/steren/prioprepare-web
chrome app: flag as offline, window not resizable and always on top
support for a 'small mode', where title and explanations are skipped
After selection, display file name instead of file input

This was needed to make the user understand that the dropped file was selected
new more modern style
Merge branch 'master' of github.com:steren/prioprepare-web