Revamp tutorial

[Geokureli]

replaces the old angle-based movement code with simpler boolean logic code, and replaced velocity.setPolarDegrees with velocity.scale(SPEED/magnitude)

@SeiferTim I'd like your thoughts on this

[SeiferTim]

I'm good with this.
The only reason I used my method was to avoid the 'go faster when diagonal' and in a way that the reader would understand... which I think your logic solves.

[Geokureli]

FYI this turned into a full blown rewrite and reskin