Revert "help.html: remove tr:hover background-color"
Revert "help.html: remove tr:hover background-color"

This reverts commit 1e37e6b941b2e263a09e605a8a7019c10e242c9d.

tgunr/factor,factor/factor,factor/factor,mrjbq7/factor,factor/factor,mrjbq7/factor,factor/factor,factor/factor,tgunr/factor,mrjbq7/factor,mrjbq7/factor,tgunr/factor,tgunr/factor,mrjbq7/factor,tgunr/factor,factor/factor,mrjbq7/factor,tgunr/factor