Adding reference link

src/shapes/path.cpp

diff --git a/src/shapes/path.cpp b/src/shapes/path.cpp
index af2b688..7aa43dc 100644
--- a/src/shapes/path.cpp
+++ b/src/shapes/path.cpp
@@ -11,7 +11,7 @@
 using namespace rive;
 
 /// Compute an ideal control point distance to create a curve of the given
-/// radius.
+/// radius. Based on "natural rounding" https://observablehq.com/@daformat/rounding-polygon-corners
 static float
 computeIdealControlPointDistance(const Vec2D& toPrev, const Vec2D& toNext, float radius) {
     // Get the angle between next and prev