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/utils/circlesintersect/readme.mdx

@@ -0,0 +1,66 @@
+---
+title: utils.circlesIntersect()
+---
+
+The `utils.circlesIntersect()` function finds the intersections between two
+circles described by their center point and radius.
+
+## Signature
+
+```js
+array | false utils.circlesIntersect(
+  Point centerA, 
+  float radiusA, 
+  Point centerB, 
+  float radiusB, 
+  string sort = 'x'
+)
+```
+
+The 5th and last parameter controls the _sorting_ of the found intersections.
+When this returns 2 intersections, you can choose how they are ordered in the returned array:
+
+Set sort to:
+
+- `x` : The point with the lowest X-coordinate will go first (left to right)
+- `y` : The point with the lowest Y-coordinate will go first (top to bottom)
+
+## Example
+
+<Example caption="A Utils.circlesIntersect() example">
+```js
+({ Point, points, Snippet, snippets, utils, part }) => {
+
+  points.A = new Point(10, 10)
+    .addCircle(15, "fabric")
+  points.B = new Point(30, 30)
+    .addCircle(35, "fabric")
+  points.C = new Point(90, 10)
+    .addCircle(15, "various")
+  points.D = new Point(110, 30)
+    .addCircle(35, "various")
+  
+  const intersections1 = utils.circlesIntersect(
+    points.A,
+    points.A.attributes.get("data-circle"),
+    points.B,
+    points.B.attributes.get("data-circle")
+  )
+  const intersections2 = utils.circlesIntersect(
+    points.C,
+    points.C.attributes.get("data-circle"),
+    points.D,
+    points.D.attributes.get("data-circle"),
+    "y"
+  )
+  
+  snippets.first1 = new Snippet("bnotch", intersections1[0])
+  snippets.second1 = new Snippet("notch", intersections1[1])
+  snippets.first2 = new Snippet("bnotch", intersections2[0])
+  snippets.second2 = new Snippet("notch", intersections2[1])
+
+  return part
+}
+```
+</Example>
+