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/prepartdraft/readme.mdx

@@ -0,0 +1,27 @@
+---
+title: prePartDraft
+---
+
+The `prePartDraft` lifecycle hook runs just before a part is drafted.
+It will fire once for each part in each set (of settings).
+
+## Signature
+
+```js
+null hook(Pattern pattern)
+```
+
+## Example
+
+```js
+pattern.on('prePartDraft', pattern => {
+  // Mutate the pattern object here
+  // You can use the pattern.activePart 
+  // and pattern.activeSet properties to
+  // figure out for which part this hook was fired
+}
+```
+
+## Notes
+
+The `prePartDraft` hook is rarely used, but it's there if you need it.