Add minimum working example

[mattxwang]

This PR is a minimum working example (or MVP) for stylelint-create. Functionally, it has a simple workflow:

1. check if the user has the right version of node
2. check if a Stylelint config already exists
3. check if package.json exists
4. if all checks pass,
   1. install stylelint and stylelint-config-standard with the package manager's installer
   2. write a message for the user with next steps

In addition, I've:

• set up the typical "Stylelint stack" of ESLint, Prettier, Remark
• wrote a simple integration test for existing Stylelint config with Vitest
• run lint + test as actions

I've been manually testing with node create-stylelint.mjs in the project root, though I'm sure that there are better ways to do this.

I do have a few things I'd like some opinions/help on!

Questions

High-level:

• should I be writing unit tests as well? or do we think integration tests are comprehensive in this case?
• I kept everything in one file since I felt that the logic wasn't too complex. Should I break things up (particularly, messages)?
• many of the ESLint norms we have aren't designed for CLI tools. Should I make adjustments locally (with comments), globally (disable rules in the config), or somewhere else?

Specific:

• should these integration tests be more comprehensive (ex examine the directory structure / last-modified times)? for now, it's mostly looking at error code + messages.
• in the tests, my approach to get the filepath for the executable and fixtures is very hacky. I struggled to find documentation on Vitest in the correct way to do this (it seems like most people are using it for Vite, or at least for web apps/server code rather than CLIs). Any thoughts?

Items Left

Let me know if we think any of these are unnecessary, or if I am missing something.

• write more integration tests:
  • happy path
  • package.json doesn't exist
  • failure during installation (I think I'll have to mock execa for this)
• add TypeScript
• test on macOS, Windows (I was planning on doing this through CI)
• better documentation

I'd love to keep working on this and add other features soon!

---

Ref: stylelint/stylelint#4269.

[ybiquitous]

Thanks for creating this MVP. It seems great as a basis!

[ntwb]

Looking great, added some comments...

[jeddy3]

Looking good!

I've made some suggestions.

I don't think we're far off having this ready. It'd be nice to roll it into the v15 launch.

[mattxwang]

Thanks everyone for chiming in - will get to addressing reviews soon! Just to be transparent, won't be able to work on this likely until Friday or the weekend (catching up after travelling for interviews)!

[ybiquitous]

I've left one question, but SGTM. Thanks!

[jeddy3]

Looking great!

I've added a minor suggestion.

[ybiquitous]

Great work! LGTM 👍🏼

[jeddy3]

Awesome stuff. I think we can merge this MVP and then pick up any improvements in new tickets and PRs.