Update default values in ortho() docs, use default args in example

Author: davepagurek

src/webgl/p5.Camera.js

@@ -205,7 +205,7 @@ p5.prototype.perspective = function (...args) {
  * maximum z values.
  *
  * If no parameters are given, the following default is used:
- * ortho(-width/2, width/2, -height/2, height/2, 0, max(width, height)).
+ * ortho(-width/2, width/2, -height/2, height/2, 0, max(width, height) + 800).
  * @method  ortho
  * @for p5
  * @param  {Number} [left]   camera frustum left plane
@@ -223,7 +223,7 @@ p5.prototype.perspective = function (...args) {
  * function setup() {
  *   createCanvas(100, 100, WEBGL);
  *   camera(0, 0, 50*sqrt(3), 0, 0, 0, 0, 1, 0);
- *   ortho(-width / 2, width / 2, height / 2, -height / 2, 0, 500);
+ *   ortho();
  *   describe(
  *     'two 3D boxes move back and forth along same plane, rotating as mouse is dragged.'
  *   );