Unescape < and > in inline code in docs

[davepagurek]

Related to processing/p5.js-website#1240. Part of the problem there was that some inline code in the reference was manually unescaped in the p5 source code, while others were not. This led to us having to try to figure out which to escape or which not to. It's probably easier for everyone if it's consistent: never manually escape in docs.

This was generated by:

• Running find src -name "*.js" | xargs perl -p -i -e 's/&lt;/</g'
• Running find src -name "*.js" | xargs perl -p -i -e 's/>/>/g'
• Manually correcting the one false positive in the diff, a function escapeHelper that maps raw symbols to escaped versions
• Tested in the p5.js-website repo using npm run custom:dev https://github.com/processing/p5.js.git#unescape

Changes:

• Instances of manual < and > in the docs are replaced by < and >

Screenshots of the change:

PR Checklist

• npm run lint passes
• Inline reference is included / updated
• Unit tests are included / updated