Change service id to /^[a-z0-9]+(?:_[a-z0-9]+)*$/

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Update links to documentation

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
Add info about repositories to porting

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>