Expand to include Userscripts

[Leamsi9]

Userscripts are like the wild west of browser extensions. They do the same as the latter, but without any vetting by the vendors. As such they are riskier, but also much more versatile. They should definitely be part of both, this repo, and our wider Green Mode Design R&D.

This ticket needs:

• Create a section in the Repo for userscripts, and add it to the TOC and the introductory blurb. Should include warning and tips
• Search through tampermonkey for keywords like CPU, disable``skip``co2 etc., in all search links provided
• Identify the highest traffic apps, then find green mode scripts for Facebook netflix, etc
• Add any promising ones with updates in the last 2 years to the repo.