ER: Support code highlighting in client

[alexbbrown]

Is your feature request related to a problem? Please describe.

For whatever reason, mastodon's web interface doesn't support markdown or code face or syntax highlighting.  But clients could!

func a() -> Int {  }

or
keyword

Describe the solution you'd like

I'd like metatext app to use appropriate fonts, and ideally colors, to show code. This would make it easier to read.

Describe alternatives you've considered

Have this supported as official mastodon feature
Automatically detect code without ``` marks.
Have a button to show ALL content as monospace

Additional context
Add any other context or screenshots about the feature request here.

Gagron's pull request is closed mastodon/mastodon#10787

[alexbbrown]

Looks like there are mastodon forks which support formatting and code highlighting.

https://glitch-soc.github.io/docs/features/rich-text/

It's not clear to me if backend support for formatting would automatically be supported in clients - I assume rendering is native in metatext (not webkit).

[alexbbrown]

Another pr / thread on the topic of integrated markdown mastodon/mastodon#18958