Fix react-markdown in production

[cquiroz]

react-markdown is being used for the help system but it fails in production.
After chasing down this issue, my conclusion is that vite/rollup has some troubles with modules using commonjs style rather than es style

vitejs/vite#2862

This is still odd because it works properly if I use it on the plain js side, thus there is something odd on the way scala.js interacts with commonjs imports

The solution I found is kind of convoluted but seems to work:

Remove the react-markdown dependency and internalize the .js files from react-markdown but convert them to es via cjstoesem

This feels very hacky but the only alternative I can think of is to reimplement in scala.
I'd like to at least test this in prod.

[rpiaggio]

👍 hope this fixes the issue in prod

[toddburnside]

🤞 👍