Fix error when creating changeset via 'npx @changesets/cli'

[deining]

Currently, when creating a new changeset via command npx @changesets/cli, an error is thrown:

🦋 ...
🦋  === Summary of changesets ===
🦋  minor:  astro
🦋
🦋  Note: All dependents of these packages that will be incompatible with the new version will be patch bumped when this changeset is applied.
🦋
🦋  Is this your desired changeset? (Y/n) · true
🦋  error Error [ERR_REQUIRE_ESM]: require() of ES Module C:\Users\xxx\GitHub\astro\prettier.config.js from C:\Users\xxx\AppData\Local\npm-cache\_npx\c21dc4ee7bbf9939\node_modules\prettier\third-party.js not supported.
🦋  error Instead change the require of prettier.config.js in C:\Users\xxx\AppData\Local\npm-cache\_npx\c21dc4ee7bbf9939\node_modules\prettier\third-party.js to a dynamic import() which is available in all CommonJS modules.
🦋  error     at module2.exports (C:\Users\xxx\AppData\Local\npm-cache\_npx\c21dc4ee7bbf9939\node_modules\prettier\third-party.js:83:61)
🦋  error     at loadJs2 (C:\Users\xxx\AppData\Local\npm-cache\_npx\c21dc4ee7bbf9939\node_modules\prettier\third-party.js:8050:22)
🦋  error     at Explorer.loadFileContent (C:\Users\xxx\AppData\Local\npm-cache\_npx\c21dc4ee7bbf9939\node_modules\prettier\third-party.js:8449:36)
🦋  error     at Explorer.createCosmiconfigResult (C:\Users\xxx\AppData\Local\npm-cache\_npx\c21dc4ee7bbf9939\node_modules\prettier\third-party.js:8453:40)
🦋  error     at Explorer.loadSearchPlace (C:\Users\xxx\AppData\Local\npm-cache\_npx\c21dc4ee7bbf9939\node_modules\prettier\third-party.js:8438:35)
🦋  error     at async Explorer.searchDirectory (C:\Users\xxx\AppData\Local\npm-cache\_npx\c21dc4ee7bbf9939\node_modules\prettier\third-party.js:8428:31) {
🦋  error   code: 'ERR_REQUIRE_ESM'
🦋  error }

This PR resolves that issue by renaming config file prettier.config.js to prettier.config.mjs.
This is in line with the README.md file of the Prettier Pugin for Astro which also suggest to use prettier.config.mjs as config file.

[changeset-bot]

⚠️ No Changeset found

Latest commit: eeb8f4d

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[florian-lefebvre]

There's a link to the prettier config in STYLE_GUIDE.md, can you update it as well?

[deining]

There's a link to the prettier config in STYLE_GUIDE.md, can you update it as well?

Done, thanks for pointing that out!

[florian-lefebvre]

Thanks!