Links to documentation in the ReadMe are outdated

[baletiballo]

The sTeX manual/documentation linked in the ReadMe seem outdated.

• The PDF of the Manual is from 2023/03. It links a HTML version on stexmmt.mathhub.info from 2025/01 with broken active document features. (I could find no version on FLAMS)
• The PDF of the Documentation is from 2024/01 and has no obvious link to a HTML version, even though there is one on FLAMS from 2025/04.