chore: Port FreeSewing.dev to docusaurus

The replaces the NextJS site powering FreeSewing.dev with a Docusaurus
setup. It's part of my efforts to simplify FreeSewing's setup so we can
focus on our core value proposition.

sites/dev/docs/reference/packages/prettier-config/readme.mdx

@@ -0,0 +1,44 @@
+---
+title: prettier-config
+---
+
+Published as [@freesewing/prettier-config][1], this package is
+FreeSewing's shared configuration for [Prettier](https://prettier.io/).
+
+## Installation
+
+```sh
+npm install @freesewing/prettier-config
+```
+
+## Usage
+
+Edit package.json:
+
+```json
+{
+  // ...
+  "prettier": "@freesewing/prettier-config"
+}
+```
+
+## Prettier options
+
+The Prettier options configured by this package:
+
+| Option | Value |
+|--------|-------|
+| semi | `false` |
+| singleQuote | `true` |
+| trailingComma | "es5" |
+| printWidth | 100 |
+
+:::note RELATED
+
+Please see the
+[Prettier options documentation](https://prettier.io/docs/en/options.html)
+for information about the effects of each option.
+
+:::
+
+[1]: https://www.npmjs.com/package/@freesewing/prettier-config