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/pd/readme.mdx

@@ -0,0 +1,61 @@
+---
+title: pd
+---
+
+The `pd` macro adds a _path dimension_ to your pattern, indicating the length
+of a path.
+
+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('pd', {
+  Number d,
+  String id,
+  Path path,
+  Boolean noEndMarker,
+  Boolean noStartMarker,
+  String text,
+  Boolean force = false,
+})
+```
+
+## Example
+
+<Example caption="An example of a path dimension with the pd macro">
+```js
+({ Point, Path, paths, macro, part }) => {
+
+  paths.example = new Path()
+    .move(new Point(0,0))
+    .curve(new Point(20,10), new Point(60,10), new Point(80,0))
+
+  macro('pd', {
+    path: paths.example,
+    d: 15,
+    force: true,
+  })
+
+  return part
+}
+```
+</Example>
+
+## Configuration
+
+| Property        | Default | Type                | Description |
+|----------------:|---------|---------------------|-------------|
+| `path`          |         | [Path](/reference/api/path)   | The path to draw the dimension along |
+| `d`             | 10      | Number              | The offset at which to draw the dimension |
+| `text`          | Path length | Number          | The text to go on the dimension if not the length of the path |
+| `id`            | `pd` | `string` | The ID of this macro instance |
+| `noStartMarker` | `false` | Boolean             | Whether to not draw a start marker |
+| `noEndMarker`   | `false` | Boolean             | Whether to not draw an end marker |
+| `force`      | `false`    | `boolean`  | Set this to `true` to display the macro output even when `paperless` is `false` |
+
+## Notes
+
+This macro takes the `paperless` setting into account and won't output anything when both `paperless` and `force` are `false`.
+