updated debian meta data

Updated the Debian manifest, 

- should contain no breaking, all changes should be cosmetic, text only
- update min mono version to 3.6 take from https://github.com/Sonarr/Sonarr/wiki/Installation#ubuntu

the reason I update the mono version is, it should be more clear for user to get an installation error and not having to post a message on the forums asking why shit is broken and us telling them to update their mono.


@Taloth @markus101