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/macros/bartack/readme.mdx

@@ -0,0 +1,60 @@
+---
+title: bartack
+---
+
+The `bartack` macro allows you to add a _bartack_ marker to your sewing
+pattern.
+
+It is provided by [plugin-annotations](/reference/plugins/annotations), which is
+part of [core-plugins](/reference/plugins/core) (so it is available by default).
+
+## Signature
+
+```js
+macro('banner', {
+  String id='bartack',
+  Point anchor,
+  Number angle=0,
+  Number density=3,
+  Number length=15,
+  String prefix='',
+  String suffix='',
+  Number width=3,
+  Boolean force = false,
+})
+```
+
+## Example
+
+<Example caption="Example of the bartack macro">
+```js
+({ macro, Point, part }) => {
+
+  macro('bartack', {
+    anchor: new Point(0,0),
+    length: 25
+  })
+
+  return part
+}
+```
+</Example>
+
+## Configuration
+
+| Property     | Default    | Type       | Description |
+|-------------:|------------|------------|-------------|
+| `anchor`     |            | `Point`    | The point to start the bartack from |
+| `angle`      | `0`        | `number`   | The angle under which to draw the bartack |
+| `density`    | `3`        | `number`   | Controls how close the stitches are together |
+| `id`         | `bartack`  | `string`   | The ID of this macro instance |
+| `length`     | `15`       | `number`   | Length of the bartack |
+| `prefix`     |            | `string`   | A prefix to apply to the name of the generated path |
+| `suffix`     |            | `string`   | A suffix to apply to the name of the generated path |
+| `width`      | `3`        | `number`   | Width of the bartack |
+| `force`      | `false`    | `boolean`  | Set this to `true` to display the macro output even when `complete` is `false` |
+
+## Notes
+
+This macro takes the `complete` setting into account and won't output anything when both complete and `force` are `false`.
+