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/api/point/attr/readme.mdx

@@ -0,0 +1,48 @@
+---
+title: Point.attr()
+---
+
+The `Point.attr()` method adds an attribute to the point, and returns the
+original point. Setting the third parameter to `true` will replace the value of
+the attribute instead of adding it.
+
+## Signature
+
+```js
+Point point.attr(
+  string name,
+  mixed value,
+  bool overwrite = false
+)
+```
+
+If the third parameter is set to `true` it will call [`this.attributes.set()`](/reference/api/attributes/set/) instead, thereby overwriting the value of the attribute.
+
+
+:::tipThis method is chainable as it returns the `Point` object:::
+
+## Example
+
+<Example caption="An example of the Point.attr() method">
+```js
+({ Point, points, Path, paths, part }) => {
+
+  points.anchor = new Point(100, 25)
+    .attr('data-text', 'FreeSewing')
+    .attr('data-text', 'rocks')
+
+  // Avoid the text getting cropped
+  paths.hidden = new Path()
+    .move(points.anchor)
+    .line(points.anchor.shift(0, 80))
+    .addClass('hidden')
+
+  return part
+}
+```
+</Example>
+
+## Notes
+
+See [Using Attributes](/howtos/code/attributes)
+for information about custom Attributes that can be used with Points.