🚀 Feature: Switch from `.yml` files to `.yaml`

[JoshuaKGoldberg]

Feature Request Checklist

• I have looked at the latest version of the project.
• I have searched for related issues and found none that matched my issue.

Overview

This repo's everything preset includes a blockESLintYML that configures eslint-plugin-yml set to enforce .yml file extensions:

create-typescript-app/eslint.config.js

Line 108 in eef0d97

"yml/file-extension": ["error", { extension: "yml" }],

But, per https://yaml.org & https://yaml.org/faq.html, it's YAML (Yet Another Markup Language). .yml is just a shorthand file extension that came out years ago for systems that couldn't handle >3-character file extensions.

https://ota-meshi.github.io/eslint-plugin-yml/rules/file-extension.html indicates the default is yaml.

Additional Info

Corresponding issue over in Flint: JoshuaKGoldberg/flint#840

[github-actions]

🎉 This is included in version v2.57.0 🎉

The release is available on:

• GitHub releases
• npm package (@latest dist-tag)

Cheers! 📦🚀