builtin support for js projects

[Gankra]

The goal of this would be to support much the same things we support for cargo projects:

• We can read your workspace/package metadata
  • largely already provided by axoproject
  • work needs to potentially be done to remove pervasive assumptions of cargo-ness
  • probably most of that work is already done by generic workspaces!
  • where does dist-specific metadata go?
• We can announce/publish libraries
  • cargo story improving in #405, should ideally have parity with that
  • introduces an ambiguity: #1169
• We can build and package your binaries
  • what this means is ambiguous but for dist providing something like bun compile-based self-contained executables sounds desirable
  • what is "the" build command?
    • where does it output?
    • what is it expected to produce?

I'm sure there's something I'm missing but all the work on generic/shared workspaces has put us surprisingly close to this Just Working.