Review of user and developer documentation

[ewl+rdiffbackup]

Hello,

the main documentation has just been revised and it would be nice if 
less involved members from this mailing list could have a look and point 
out where they can't follow or if something is missing:

users: https://github.com/rdiff-backup/rdiff-backup/blob/master/README.md

developers: 
https://github.com/rdiff-backup/rdiff-backup/blob/master/docs/DEVELOP.md

We just need new eyes to point at what we don't see anymore :-)

Thanks, Eric