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/path/attr/readme.mdx

@@ -0,0 +1,56 @@
+---
+title: Path.attr()
+---
+
+This `Path.attr()` method can be used to add attributes to the Path object.
+It calls `this.attributes.add()` under the hood, and returns the Path object.
+
+If the optional third parameter is set to `true` it will call `this.attributes.set()`
+instead, thereby overwriting the value of the attribute.
+
+## Signature
+
+```js
+Path path.attr(
+  string name,
+  mixed value,
+  bool overwrite = false
+)
+```
+
+:::tipThis method is chainable as it returns the `Path` object:::
+
+## Example
+
+<Example caption=" Example of the Path.attr() method">
+```js
+({ Point, points, Path, paths, part }) => {
+
+  points.from = new Point(10, 20)
+  points.cp1 = new Point(20, -10)
+  points.cp2 = new Point(50, 50)
+  points.to = new Point(70, 20)
+
+  paths.example = new Path()
+    .move(points.from)
+    .curve(points.cp1, points.cp2, points.to)
+    .attr("class", "canvas")
+    .setText("FreeSewing rocks", "text-xs center")
+
+  return part
+}
+```
+</Example>
+
+
+## Notes
+
+Methods like
+[`Path.addClass`](/reference/api/path/addclass),
+[`Path.setClass`](/reference/api/path/setclass),
+[`Path.addText`](/reference/api/path/addtext), and
+[`Path.setText`](/reference/api/path/settext)
+all call this method under the hood.
+
+See [Using Attributes](/howtos/code/attributes)
+for information about custom Attributes that can be used with Paths.