add valuable informations to README
Originally reported in July 2017 here https://bugzilla.gnome.org/show_bug.cgi?id=785286
The README file is empty.
I would suggest to add infos about
- the project website and the overall project (Gnome)
- link to upstream source (the git-repo on gnome)
- link to a docu about how to contribute, bug report or communicate (via mailinglist, irc, whatever) with upstream
It is also related to a reported Debian Bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=869277