Persumable you mean the pgjdbc github repo and not the postgresql one :)
That said, it would probably make sense to list URLs for the most common projects. Right now we just say "there may be a mailinglist available". Perhaps we should directly link to the correct mailinglist and/or issues page for those projects that are most common. That would be pgjdbc and pgadmin i guess, and maybe some others. pgodbc? Any more?