Add ability to page scroll ROMs by first letter

[Erik Johnson]

Is your feature request related to a problem? Please describe.
Excessively large ROM sets

Describe the solution you'd like
I really like start/select as pagination for the rom selection, but also perhaps add the ability to hold another key while paginating to skip to the first #xx, Axxx, Bxx, Cxx etc listing. such as holding B since B has no function in these screens