Key descriptions: HELP listed twice, F9 is not

[Rhialto]

In the freezer menu, there are two mentions of the HELP key (fortunately the same).

The F9 key does something (seemingly the same as F3) but it not explained. Perhaps it is meant to do nothing.

[lydon42]

Fix for HELP in 724c57f

[lydon42]

The problem with F9 stems from the joystick support as it seems. That will trigger an unwanted char. So either we make this more solid, or we need to disable it for the standard machines (I think it's a megaphone feature...)

[lydon42]

It's coming through $DC01. If we only look at $DC00 the problem will go away. I am open for other solutions to read joystick without confusing it with keyboard...