Port references from p5.js

Which area of the website does this enhancement relate to?

Reference

Describe the enhancement

Hello! Long-time coder, first-time contributor.

A team recently revised the p5.js reference to make it more accessible. Many of the opportunities we found to improve the p5.js reference are shared by Processing. I propose porting our work to Processing, starting with the pages for 2D Primitives.

• [ ] arc
• [ ] circle
• [ ] ellipse
• [ ] line
• [ ] point
• [ ] quad
• [ ] rect
• [ ] square
• [ ] triangle

Why is this enhancement important?

Processing's reference can be made more accessible by ensuring the use of plain language, providing beginner-friendly examples, and improving consistency between reference pages. The p5.js Documentation Style Guide outlines the approach, which could be adapted to enhance Processing's Style Guidelines.

Additional context

I was the lead author of the p5.js reference rewrite and currently teach with Processing in my AP CSP and CSA classes. My schedule is opening up, so I'd love to begin contributing to the reference.