Add publint

[NullVoxPopuli]

I originally thought this might be blocked on

• Set type=module #6

but that is not the case (it certainty used to be) -- output actually looks pretty good in an empty project:

Running publint v0.3.16 for my-addon...
Packing files with `pnpm pack`...
Linting...
All good!

An example with an error:

Linting...
Errors:
1. pkg.exports["."].default is ./dxist/index.js but the file does not exist.

This is what the tool offers:

❯ pnpm publint --help

  Usage
    $ publint <command> [options]

  Available Commands
    run     Lint a directory or tarball file path (defaults to current directory)
    deps    Lint dependencies declared in package.json (deprecated)

  For more info, run any command with the `--help` flag
    $ publint run --help
    $ publint deps --help

  Options
    --level          Level of messages to log ('suggestion' | 'warning' | 'error')  (default suggestion)
    --pack           Package manager to use for packing ('auto' | 'npm' | 'yarn' | 'pnpm' | 'bun' | false)  (default auto)
    --strict         Report warnings as errors  (default false)
    -v, --version    Displays current version
    -h, --help       Displays this message

[ef4]

Notes from tooling team discussion: giving people warnings in the out-of-the-box experience is not good, particularly when some of those warnings are giving bad advice:

Consider adding "type": "commonjs".

[NullVoxPopuli]

@ef4 tyty -- those issue are resolved via setting --level error, which means anything "non-critical" isn't printed (in the latest commit).

Also, I've opened publint/publint#211 so we can get an idea of what is errors, warnings, suggestions, etc (so we can see what we're missing out on via ignoring warnings and suggestions entirely)