Now I know all the buzzwords for how it's run, but still not what it actually does.

Watch the video it's a 101-style how/what/why etc.

Not going to watch a 10 minute video for that, sorry (especially not on mobile), and I don't think I'm alone in that. It's just a bad medium for initial impressions unless done really well and compressed.

EDIT: on second read of the GitHub readme I understood that the text examples are commands you can give and not examples of what the bot does, that makes it clearer. Still, if you submit a blogpost that IMHO should be in the post.

Example / walk-through - https://github.com/Subsurface-divelog/subsurface/pull/1137