This is the easiest way to add votesites. Simply vote and a votesite will generate in VoteSites.yml with the correct Service Site.
This requires that votifier is working and setup properly. This is enabled by default in Config.yml.
External editor with sftp support
Available here
Create a votesite manually in VoteSites.yml. Just make sure to set the correct Service Site.
Create ingame, /av gui (Middle click votesites)