Keyboard interaction hints available on touch screens

[jessegreenberg]

From #206

@KatieWoe mentioned that this hint is available on iOS VoiceOver, even though there is no keyboard.

also noticed that the instructions will include things like using the wasd keys and the 123 autoslide options, despite this being the iPad version of the sim with no keyboard nav dialog

This kind of thing needs to be removed on touch screens.

[jbphet]

I believe that this doesn't need to be a publication-blocking bug for the 1.4 release. It only occurs on iOS devices when using VoiceOver, and the sim is still fully usable, it's just potentially a bit confusing. When a fix for this is available, please assign the issue to me and I'll do a maintenance release from the 1.4 branch with the changes.