Add progressive TypeScript compilation

[sarayourfriend]

Fixes

Fixes #175 by @sarayourfriend

Description

Replaces jsconfig.json with a tsconfig.json that mirrors Gutenberg's with some changes to accomodate not being a composite project.

Currently this only checks a single file, basically in an effort to minimize the size of this PR while also still proving that it does work as intended. I had to make a small update to the type declarations in this file to get the compiler to pass. Hooray for type feedback! 🎉

Future work will include slowly adding each file in src/composables to the include array. We can also start running the type checker on other parts of the codebase like the services 🙂 I would propose doing this in small isolated bits and pieces to avoid having to make too many changes in a single PR to address the inevitable error here and there.

Testing Instructions

Checkout the PR and run npm run types. Everything should come back without an error. Next, update use-event-listener-outside.js to include a type error. For example, add the following somewhere in the file:

/** @type {string} */
const foo = null

This is a type error becuase you can't assign null to a string. Your IDE should pick this up and give you some squiggly lines or a warning (however your IDE normally picks up compilation errors). You should now also be able to run npm run tsc and have it report back the error to you.

Go ahead and try to commit that (you'll have to disable the eslint no-unused-vars rule temporarily to be able to run the pre-commit) and pre-commit should fail on the tsc step.

Checklist

• My pull request has a descriptive title (not a vague title like Update index.md).
• My pull request targets the default branch of the repository (main) or a parent feature branch.
• My commit messages follow best practices.
• My code follows the established code style of the repository.
• I added or updated tests for the changes I made (if applicable).
• I added or updated documentation (if applicable).
• I tried running the project locally and verified that there are no visible errors.

Developer Certificate of Origin

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[zackkrida]

Nice! Adding a type error produced the expected result.

[zackkrida]

npm run format:test is warning on the tsconfig.json file, however...

[obulat]

Great start! I tried adding use-related to the include array - and Oh wow, it's so much work :)

[dhruvkb]

This is a major boost for DX!

[krysal]

This extra help with types is excellent! ✨