Modify rect and ellipse comments

In the `CORNERS` mode, rectangles and ellipses are drawn based on two points/corners.

Author: mrmowji

src/templates/pages/learn/coordinate-system-and-shapes.hbs

@@ -87,7 +87,7 @@ function setup(){
   rectMode(CORNERS);
 }
 function draw(){
-  rect(10, 10, 50, 30); // rect(x, y, width, height)
+  rect(10, 10, 50, 30); // rect(x1, y1, x2, y2)
 }
 </script>
 
@@ -118,7 +118,7 @@ function setup(){
   ellipseMode(CORNERS);
 }
 function draw(){
-  ellipse(10, 10, 40, 50); // ellipse(x, y, width, height)
+  ellipse(10, 10, 40, 50); // ellipse(x1, y1, x2, y2)
 }
 </script>