[Docs] Fragment masses are present

[jspaezp]

The parameter was removed here:
d1280a7

But the documentation still shows it as existing:

• https://sage-docs.vercel.app/docs/configuration
• https://github.com/lazear/sage/blob/master/DOCS.md
• ... benchmark configs ... where you might want to leave it ... or not...

LMK if you want PR for the cleanup (I have no idea where the source for the vercel site is ...)

[lazear]

A PR would be great - docs are here: https://github.com/lazear/sage-docs