Add scroll key word to note entry speed and touch note entry speed options

[ziv-vy]

So that, when mania players search for "scroll", they get note entry speed options too. Or just rename these to "Note scroll speed" and "Touch entry scroll speed".

[LumpBloom7]

"Note scroll speed is fine", but "Touch note scroll speed makes 0 sense"

Adding it as a hidden keyword does make sense though