Support syndicate-to targets.

[miklb]

Name on the tin says it all. Didn't see an open issue for this. I'm not sure what the intended action is supposed to be for instance when liking a tweet with Tweetbot.

[EdwardHinkle]

Great point! Currently my server doesn't support syndicate-to so that wasn't on the list but it definitely should be! I actually have an idea on how this should be implemented interface-wise too so I'll try to see if we can put that in the next build.

Thanks :)

[EdwardHinkle]

Dev notes:
https://www.w3.org/TR/micropub/
https://indieweb.org/syndicate-to
https://indieweb.org/Micropub#h-entry

[EdwardHinkle]

Based on conversations in indieweb-dev IRC, likes shouldn't really have posting options, so the best approach to this is having default syndicate-to targets based on patterns (twitter.com, github.com) and allowing the user to set which syndicate targets for each pattern.

(https://chat.indieweb.org/dev/2017-11-13#t1510587977681000)