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/join/readme.mdx

@@ -0,0 +1,59 @@
+---
+title: Path.join()
+---
+
+The `Path.join()` method joins this path with one or more other paths.
+
+Any gaps in the path (caused by move operations) will be filled-in with a line.
+If that's not what you want, you should use
+[`Path.combine()`](/reference/api/path/combine) instead.
+
+
+## Signature
+
+```js
+Path path.join(path other)
+```
+
+## Examples
+
+<Example caption="Example of the Path.join() method">
+```js
+({ Point, points, Path, paths, part }) => {
+
+  points.A1 = new Point(0, 0)
+  points.A2 = new Point(60, 0)
+  points.B1 = new Point(0, 10)
+  points.B2 = new Point(60, 10)
+  points.C1 = new Point(0, 20)
+  points.C2 = new Point(60, 20)
+
+  paths.path1 = new Path()
+    .move(points.A1)
+    .line(points.A2)
+    .setClass("various")
+
+  paths.path2 = new Path()
+    .move(points.B1)
+    .line(points.B2)
+    .setClass("note")
+
+  paths.path3 = new Path()
+    .move(points.C1)
+    .line(points.C2)
+    .setClass("canvas")
+
+  paths.joint = paths.path1
+    .join(paths.path2, paths.path3)
+    .setClass("lining dotted")
+
+  return part
+}
+```
+</Example>
+
+
+## Notes
+
+- `Path.join()` is _variadic_, so you can pass multiple paths to join
+- You cannot join a closed path to another path