Add support for ESM plugins

[ybiquitous]

Which issue, if any, is this issue related to?

Closes #7327

Is there anything in the PR that needs further explanation?

In addition, this change does the following:

• improve the migration guide for v16
• rewrite the writing plugin guide for ESM
• make the changelog items more consistent

Note: I realized that #7279 produced a breaking change in stylelint.utils.checkAgainstRule.

[changeset-bot]

🦋 Changeset detected

Latest commit: af6d743

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

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stylelint	Major

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[jeddy3]

Fantastic! @ybiquitous It's incredible to see this, and it was only made possible by your immense effort to migrate the entire codebase to ESM!

I've tested this branch locally with a mix of ESM and CommonJS plugins. It all worked well.

I've made some minor suggestions to the wording and code style.

Let's also add something to the migration guide. We can adopt the v15 format of "significant or breaking changes". For example:

# Migrating to 16.0.0

This release contains significant or breaking changes.

## Significant changes

- added support for ESM plugins

### Added support for ESM plugins

You can now create ESM plugins for Stylelint. This involved a year-long effort to migrate our codebase to ESM. We've updated our [developer guide](../developer-guide/plugins.md) with examples of ESM syntax.

## Breaking changes

This release contains breaking changes. We've:

- removed deprecated stylistic rules
- removed support for Node.js less than 18.12.0
- changed `.js` extension to `.mjs` and `.cjs`
- changed Node.js API returned resolved object
- changed Node.js API `stylelint.formatters` object
- changed Node.js API `stylelint.rules` object
- changed Node.js API `stylelint.utils.checkAgainstRule` function
- changed CLI to print problems to stderr
- changed CLI exit code for flag errors

### Removed deprecated stylistic rules

...

The rest of the headings will need to be bumped down a level too.

Let's do another prerelease after this PR is merged.

I'll create a follow-up issue about deprecating CommonJs plugins.

[ybiquitous]

@jeddy3 Thanks a lot for the review. I've addressed and resolved all your review comments. 👌🏼

In addition, I've pushed one more improvement (101f65e) in the docs to clarify the stylelint.utils function notations, appending () like this:

-`stylelint.utils.report`
+`stylelint.utils.report()`

Any thoughts?

[jeddy3]

The changes look good. As part of this PR, let's update the migration guide.

[ybiquitous]

As part of this PR, let's update the migration guide.

Done! acd12ed

[jeddy3]

Wonderful, LGTM.

(I think we can merge and do another prerelease.)

[ybiquitous]

Okay, I'll merge this PR and release 16.0.0-2 from now.

[ybiquitous]

Done! https://github.com/stylelint/stylelint/releases/tag/16.0.0-2