feat: Flat import of markdown repo

This is a flat (without history) import of (some of) the content
from our markdown module.

We've imported this without history because the repo contains our
blog posts and showcases posts content prior to porting them to strapi.

Since this contains many images, it would balloon the size of this repo
to import the full history.

Instead, please refer to the history of the (archived) markdown repo
at: https://github.com/freesewing/markdown

markdown/dev/reference/api/utils/beamintersectscircle/en.md

@@ -0,0 +1,80 @@
+---
+title: beamIntersectsCircle()
+---
+
+```js
+array | false utils.beamIntersectsCircle(
+  Point center, 
+  float radius, 
+  Point point1, 
+  Point point1, 
+  string sort = 'x'
+)
+```
+
+Finds the intersection between an endless line through points `point1` and `point2`
+and a circle with its center at point `center` and a radius of `radius` mm.
+
+The 5th and last parameter controls the *sorting* of the found intersections.
+This will (almost) always return 2 intersections, and 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 part="utils_beamintersectscircle" caption="A Utils.beamIntersectsCircle() example" />
+
+```js
+let {
+  Point,
+  points,
+  Path,
+  paths,
+  Snippet,
+  snippets,
+  utils
+} = part.shorthand();
+
+points.A = new Point(45, 45)
+  .attr("data-circle", 35)
+  .attr("data-circle-class", "fabric");
+points.B = new Point(5, 50);
+points.C = new Point(25, 30);
+points.D = new Point(5, 65);
+points.E = new Point(65, 5);
+points.F = new Point(15, 75);
+points.G = new Point(75, 15);
+
+paths.line1 = new Path().move(points.B).line(points.C);
+paths.line2 = new Path().move(points.D).line(points.E);
+paths.line3 = new Path().move(points.F).line(points.G);
+
+let intersections1 = utils.beamIntersectsCircle(
+  points.A,
+  points.A.attributes.get("data-circle"),
+  points.B,
+  points.C
+);
+let intersections2 = utils.beamIntersectsCircle(
+  points.A,
+  points.A.attributes.get("data-circle"),
+  points.D,
+  points.E,
+  "y"
+);
+let intersections3 = utils.beamIntersectsCircle(
+  points.A,
+  points.A.attributes.get("data-circle"),
+  points.F,
+  points.G
+);
+
+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]);
+snippets.first3 = new Snippet("bnotch", intersections3[0]);
+snippets.second3 = new Snippet("notch", intersections3[1]);
+```