I learned about TILs in Simon Willison's, Weblog. He pointed to John Branchaud, who explains a TIL:
A collection of concise write-ups on small things I learn day to day across a variety of languages and technologies.
He used an automatic README.md generation with a database in other site and some other rather complex stuff. I just process the folders and create the README from til.md using GitHub Actions.
Check the TIL about Actions in GitHub to learn how I did it.
Some TILs are in my first language, Portuguese