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/api/pattern/use/readme.mdx

@@ -0,0 +1,38 @@
+---
+title: Pattern.use()
+---
+
+The `Pattern.use()` method will load a FreeSewing plugin.
+Plugins are a way to extend a pattern's functionality.
+For more details, refer to [the plugin guide](/guides/plugins/).
+
+:::noteThis method is chainable as it returns the Pattern object:::
+
+## Pattern.use() signature
+
+```js
+Pattern pattern.use(object plugin)
+// or
+Pattern pattern.use(object plugin, object plugin_data)
+```
+
+See [the plugin guide](/guides/plugins/) for details on how to structure
+you plugin object.
+
+## Pattern.use() example
+
+```js
+import { Aaron } from "@freesewing/aaron"
+import { pluginTheme } from "@freesewing/plugin-theme"
+
+// Load some public test measurements from the FreeSewing backend
+const measurements = (
+  await (
+    await fetch("https://backend3.freesewing.org/curated-sets/1.json")
+  ).json()
+).measurements
+
+const pattern = new Aaron({ measurements }).use(pluginTheme)
+
+const svg = pattern.draft().render()
+```