Comment references are extremely wordy

Currently we lower comment references as just plain URLs. For instance:

Ryan Scott @RyanGlScott commented 1 week ago

Oops, I intended to make https://gitlab.staging.haskell.org//ghc/ghc/issues/16361#note_163211 in a different ticket. Sorry about the noise.

The URL here is extremely distracting. We should rather lower this as a link with sensible anchor text (e.g. ticket:16361#comment:1).