Fixed some grammar in ingame help and added info about the "Keep hands free" option.

Did some proofreading of the ingame help, tried to break up a few long sentences and keep the style consistent.
Probably got overzealous on this one - I remember at least one occurence of semicolon being used to facilitate super long sentences (so instead of full stop). Here its use is somewhat justified at least, however I still feel that a dash fits better here. Here we have a cause and effect (also a summary of the sentence in a way) - a perfect place to use a dash. Semicolon is usually better used to connect two more loosely related main clauses. I do agree that it's a style choice, though.