publish the reference implementation and harness to npm

[lex00]

Part of #3.

What

Publish packages/reference/ and the conformance harness to npm so an independent implementation can run the suite without vendoring this repo.

Why it is not premature

The conformance suite's value is that someone who is not us can run it. Until it is installable that claim is theoretical, and the first person to test it will be a reviewer.

Decide

• package names, and whether the harness ships separately from the reference implementation (it should — an implementation under test needs the harness and should not have to install a competing implementation to get it)
• versioning against the spec version from spec: versioning policy and changelog #18
• whether chant consumes the published package or a workspace link for the cross-check in run the conformance fixtures against chant and assert agreement #11

Done when

A fresh checkout of something that is neither this repo nor chant can install the harness, write an adapter, and get a conformance report.