Serve precompiled JavaScript to the browser

Reason

It would be nice to be able to directly import TypeScript modules from the browser without having to use deno bundle.

Suggestions

• Every TypeScript should be compiled once to JavaScript.
• If User-Agent is Deno/<VERSION> or Accept contains application/typescript, serve TypeScript code. If User-Agent is one of the browsers and Accept is */*, serve JavaScript code. If Accept contains text/html, serve HTML document. Otherwise, serve TypeScript code.

[crowlKats]

we are currently doing various architectural changes to the registry and website, so any PRs will get invalid pretty quickly. I will bring this up internally once our reworks are completed

[Ciantic]

@wojpawlik This creates the overhead of having to bundle things, but that is probably rather advantageous keeping in mind that the browser can load all JS with a single request, rather than one request per module.

Neat tool, I just think these external bundlers have problem, do they exist five years from now? If they get popular the bandwidth costs etc. start to stack up. It would be nice to have official way to get JS files from deno.land directly.

Bundling as one JS file should be optional, sometimes I want just couple of neat functions from functional libraries and not all.