Update basics

See merge request docs/docs.beagleboard.io!159

reference: https://pygments.org/docs/lexers/#module-pygments.lexers.diff

Site editing guide, link button, remove slug, forward latest to root, and custom 404.html template

See merge request docs/docs.beagleboard.io!157

this template page is not required now

Merge branch 'main' of git.beagleboard.org:lorforlinux/docs.beagleboard.io; branch 'main' of https://git.beagleboard.org/docs/docs.beagleboard.io

Added instructions for learning what UU is in the output of i2cdetect.

See merge request !156