Tracking list of tmemes improvements

[creachadair]

This issue is a copy of the original TODO list we wrote during development.

Add anything you think should be done, even if you don't want to do it yourself.

• (mjf) See about writing some kind of blog post about this experience. We
  agreed this was like a really fun hackathon or "LAN party programming".
  Maybe something for .dev or a culture post on the main blog?
• (maisem) show macros by user
• (maisem) add slack integration [partly done?]
• (mjf) add a "viewed" counter?
• (jenny) add up/down vote
• (mjf) clean up the macro cache periodically in the background
• (mjf) downsize big templates when they're uploaded
• (mjf) self-updating timeline on the macros view or maybe a new view?
• (mjf) allow text colour and scale to be adjusted in the UI
• (mjf) more flexible text placement in the UI (more lines, locations)
• (mjf) support pagination for /api/templates too
• (mjf) paint text with a contrast-colour outline
• (jenny) support pagination in the frontend
• (jenny) support toggling sort order in the frontend
• (jenny) support showing memes per creator
• (mjf) support long polling to refresh the UI, like a websocket or SSE
• (mjf) render timestamps on the browser so they show the user's local time.
• (mjf) support cache control headers for image data
• (s) generate macro preview in go (wasm)
• (s) allow arbitrary number of overlays in the UI
• (s) handle multiple files dropped for upload
• (s) move upload form to top of templates page?
• (mjf) allow captions to have timed visibility (suggested by Brad)
• (mjf) allow specifying/adding context links to macros