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/snippets/readme.mdx

@@ -0,0 +1,29 @@
+---
+title: Snippets
+---
+
+A Snippet is a reusable bit of markup that draws graphic elements on patterns.
+Snippets are provided by [plugins](/reference/plugins) and are implemented as
+[`defs` elements](https://developer.mozilla.org/en-US/docs/Web/SVG/Element/defs)
+in the rendered SVG document.
+
+## Signature
+
+To place a Snippet at a given point:
+```js
+const snippet = new Snippet(String 'snippet name', Point anchor)
+```
+
+:::note RELATED
+See the [Snippet API](/reference/api/snippet)
+for more information about how to use Snippets in code.
+
+See [Using Attributes](/howtos/code/attributes)
+for information about custom Attributes that can be used with Snippets.
+:::
+
+## List of snippets
+
+Below are all the different snippets we maintain.
+
+<ReadMore />