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/presetdraft/readme.mdx

@@ -0,0 +1,35 @@
+---
+title: preSetDraft
+---
+
+The `preSetDraft` lifecycle hook runs just before a set (of settings) is
+drafted. It will fire once for each set when calling `Pattern.draft()`.
+
+## Signature
+
+```js
+null hook(Pattern pattern)
+```
+
+## Example
+
+```js
+pattern.on('preSetDraft', pattern => {
+  // Mutate the pattern object here
+}
+```
+
+## Notes
+
+The `preSetDraft` fires once for each set in the pattern.
+
+The pattern tracks the active set on the `activeSet` property. 
+So if you are using this hook and would like to get access to teh active set, you can do so like this:
+
+```js
+pattern.on('preSetDraft', ({ settings, activeSet }) => {
+  const set = settings[Number(activeSet)]
+
+  // Now set holds the active set of settings
+}
+```