Draft: what the JS/HTML template building might look like

[wegry]

I'd like for the building and loading of playgrounds to look something like this list

• stitches a module with a default export together with a very basic playground runtime.

• Compile JS and HTML templates once instead of per request

• extract playground instance source from the document tree

• map playground instance source with a content hash

• cache playground instance builds after the first

• Figure out a way around loading React from a CDN. For now this uses nodeLinker: node_modules.

[wegry]

@mariuswilms I think the basic concept is outlined here. It's very rough, but the biggest thing between getting this off the ground now is, I think, the parse/rewriting in node_doc_transformer.go. Maybe you'd like to take a stab at that?

I'll confess I'm tempted to say something like https://github.com/russross/blackfriday with https://pkg.go.dev/github.com/russross/blackfriday/v2#HTMLRenderer.RenderNode changed might fit our needs.

[mariuswilms]

@wegry I've rebased your changes and merged them into #139 and fitted them together with the code I've wrote. I'm closing this PR in favor of #139, let's continue our work there.

I'm commenting on that PR on the status,