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/pointonline/readme.mdx

@@ -0,0 +1,72 @@
+---
+title: utils.pointOnLine()
+---
+
+The `utils.pointOnLine()` function returns `true` if the point `check` lies on a
+line segment from point `from` to point `to`.
+
+## Signature
+
+```js
+bool utils.pointOnLine(
+  Point from, 
+  Point to, 
+  Point check, 
+  float precision = 1e6
+)
+```
+
+The fourth parameter controls the precision. 
+See [pointOnBeam](/reference/api/utils/pointonbeam).
+
+## Example
+
+<Example caption="A Utils.pointOnLine() example">
+```js
+({ Point, points, Path, paths, Snippet, snippets, getId, utils, part }) => {
+
+  points.from1 = new Point(10, 10)
+  points.to1 = new Point(90, 60)
+  points.from2 = new Point(10, 30)
+  points.to2 = new Point(90, 80)
+  points.b1 = new Point(170, 110)
+  points.b2 = new Point(170, 130)
+  
+  const scatter = []
+  for (let i = 1; i < 36; i++) {
+    for (let j = 1; j < 27; j++) {
+      scatter.push(new Point(i * 10, j * 10))
+    }
+  }
+  let snippet
+  for (let point of scatter) {
+    if (utils.pointOnLine(points.from1, points.to1, point)) snippet = "notch"
+    else snippet = "bnotch"
+    snippets[getId()] = new Snippet(snippet, point)
+    if (utils.pointOnLine(points.from2, points.to2, point, 0.01)) {
+      snippet = "notch"
+    } else snippet = "bnotch"
+    snippets[getId()] = new Snippet(snippet, point)
+  }
+  paths.line1 = new Path()
+    .move(points.from1)
+    .line(points.to1)
+    .addClass("fabric stroke-lg")
+  paths.lne1 = new Path()
+    .move(points.to1)
+    .line(points.b1)
+    .addClass("fabric dashed")
+  paths.line2 = new Path()
+    .move(points.from2)
+    .line(points.to2)
+    .addClass("fabric stroke-lg")
+  paths.lne2 = new Path()
+    .move(points.to2)
+    .line(points.b2)
+    .addClass("fabric dashed")
+
+  return part
+}
+```
+</Example>
+