Add Dates of Sites added on Supported Sites Page

[BosonHair]

It'd be great to add a column on the supported sites page with the date new sites were added.

[Hrxn]

Hmm.. well, might be nice to have. But is this really important?

[BosonHair]

Yeah, it's just a nice to have. New things are added all the time, be cool to see when it was added. Not saying add for previous stuff, just a cool feature moving forward.

[mikf]

You can get this information via the git commit history for this file or via git blame

While I do want to want to (slightly) update the format of docs/supportedsites, I kind of don't want to include commit-based information that rely on git and parsing git output. I would like to keep it to information contained within repository files.