Universal Tampermonkey Text Editor

I’m looking for a clean, well-commented Tampermonkey userscript that can sit in my browser and let me rewrite or insert snippets of text on any site I choose. The idea is to keep the core logic universal, then expose a simple place in the code where I can drop in my own rules—whether that’s swapping words, adding a sentence, or reshaping a headline. Because I may target very different pages over time, the script needs: • A lightweight way to scope rules per domain or URL pattern. • Multiple matching methods I can toggle (keywords, CSS selectors, or even a regex block if needed). • A plain object or JSON section at the top where I declare “find / replace / insert” instructions without touching the main logic. Please write it in vanilla JavaScript, rely only on the Tampermonkey/Greasemonkey API, and comment each section so I understand what’s happening. When you hand it over, include a quick read-me explaining where to paste new rules and how to limit them to specific sites. I’ll consider the job done when I can install the script, add a sample rule myself, refresh a page, and see the text change instantly.

Project ID: 40539731