Feature request: links.jf2 sortby param

[tantek]

Currently, webmention.io jf2 results are h-entry items sorted by most recent (dt-published) first.

There are examples where other sortings would be useful, e.g. RSVPs for yes before no before maybe before interested. (Aside: slightly regretting not using "decline" for RSVP "no" as that would sort better, though since p-rsvp is an enum, we could define a canonical ordering of the rsvp enums as: no,interested,maybe,yes in increasing/up order)

One way of doing this would be a ?sortby query param for the links.jf2 endpoint, that would take a single property name for now (with optional up or down(default)?) e.g.
?sortby=rsvp
?sortby=published
?sortby=updated

or ?sortby="published up" for earliest first sorting (e.g. what you would display in a comments section, or perhaps even an ordered facepile)