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/howtos/code/adding-paths/readme.mdx

@@ -0,0 +1,30 @@
+---
+title: Adding paths
+---
+
+Paths should be stored in the `paths` key of the object passed to your part's
+draft method. The constructor for paths is available in the `Path` key. You can
+destructure them for easy access.
+
+<Example caption="An example of adding a path" tutorial>
+```design/src/part.mjs
+function draftPart = ({ 
+  Point,
+  // highlight-start
+  Path, 
+  paths,
+  // highlight-end
+  part 
+}) {
+
+  // highlight-start
+  paths.demo = new Path()
+    .move(new Point(0,0))
+    .line(new Point(100,20))
+    .addClass('lining lashed')
+  // highlight-end
+
+  return part
+}
+```
+</Example>