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/hooks/prerender/readme.mdx

@@ -0,0 +1,20 @@
+---
+title: preRender
+---
+
+The `preRender` lifecycle hook is triggered just before your pattern is
+rendered to SVG.
+
+## Signature
+
+```js
+null hook(Svg svg)
+```
+
+## Notes
+
+The `preRender` hook is typically used to change the result of the render, for
+example by adding CSS to the SVG output.
+
+Like the `postRender` hook, it receives [the SVG object](/reference/api/svg) as its first
+parameter.