git ssb

Invite notes

I realized I've generated and given away various invite codes to @pub_cel, and now I see the pub follow feeds and I'm not sure who the people are. This PR is a simple change to allow giving an invite code a note when generating it, a piece of a text for the sbot to internally associate with the invite code. Then when the code is used, the sbot puts the note in the contact message when it follows the feed that is using the invite code. This would allow the pub operator and others to get a better idea of where a peer is coming from - whether they used a public code from the internet, or were at an event, or used a one-time code that was given to a specific person, etc.

https://git.scuttlebot.io/%25M0TrM%2BoJT2i%2FphUJO%2FfZ2wkK2AN2FB1xK0tqR7SNj58%3D.sha256/commit/69b89f6f0bf0128f0a22b579bcba5157df95a37d

Totally merging this! This means we'll need to update the various renderers. I was wondering if it should be text which might get it to display as intended by default, but then I thought about it and it would only use that if it falls back to nothing. But displaying a note property on any(?) message could be handy for future things too?

@dominic @mmckegg ping

note: i'm rendering this as "from" in patchfoo. e.g. for %t7EPDdb...:

@pub_cel 11 hours ago autofollows @gvenk from https://github.com/ssbc/scuttlebot/wiki/Pub-Servers