Update timeStepDuration to 0.1 s

[arouinfar]

For phetsims/qa#524

When stepping through a collision, things can be a bit jerky looking. We use a time step of 0.1 s in a lot of sims, and I think it works nicely here too.

@brandonLi8 if you don't have any objections, can we change timeStepDuration to 0.1 s?

[brandonLi8]

@arouinfar I'm assuming you meant 0.01s? I changed the default to 0.01 in the commit above (used to be 0.03). I'll assign back to you to make sure. Close if this is good.

[arouinfar]

Thanks for being a mindreader @brandonLi8! I did indeed mean 0.01 s. 🤦‍♀️

Looks great in dev.33!