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/inserttext/readme.mdx

@@ -0,0 +1,55 @@
+---
+title: insertText 
+---
+
+The `insertText` lifecycle hook is called when text is about to be inserted
+during rendering.
+
+It is typically used for translation, as is the case
+in [our i18n plugin](/reference/plugins/i18n/).
+
+## Signature
+
+```js
+string hook(string locale='en', string text)
+```
+
+## Example
+
+```js
+// Let' get LOUD by turning everything into UPPERCASE
+pattern.on(
+  'insertText', 
+  (locale, text) => text.toUpperCase()
+)
+```
+
+## Notes
+
+When we say that _this hook is called when text is about to be inserted_, that is a simplified view.
+In reality, this hook is called:
+
+- For every string of text added to a given Point or Path
+- For the combined result of these values, joined together with spaces
+
+Let's use an example to clarify things:
+
+```js
+points.example
+  .addText("seamAllowance")
+  .addText(": 1 cm")
+```
+
+For the example point above, the `insertText` hook will end up being called 3 times:
+
+- First it will pass `seamAllowance` to the plugin
+- Then it will pass `: 1 cm` to the plugin
+- Finally it will pass `seamAllowance : 1 cm` to the plugin
+
+Having the `insertText` hook only run once with `Seam allowance: 1 cm` would be problematic because
+the seam allowance may differ, or perhaps we're using imperial units, and so on.
+
+Instead, you can (and should) divide your text into chunks that need translating, and chunks that do not.
+
+This is also why we're not inserting **Seam allowance** but rather **seamAllowance**;
+It is merely a key to indicate what translation we want to replace this text with.