Sticky play/stop buttons in reference code examples #1385

Increasing Access

The make p5.js reference more usable, sticky play/stop buttons would help users run sketches without having to scroll.

Most appropriate sub-area of p5.js?

Reference

Feature request details

For example: https://beta.p5js.org/reference/p5/beginContour/ contains longer examples.

But when the user scrolls to edit the latter part of the sketch, the preview and play/stop controls are no longer visible:

This issue is about making the sketch square and the play/stop visible. PR should contain tests where possible.