Change hint for Keyboard Shortcuts

[terracoda]

@jessegreenberg, just tested Ohm's Law dev 20

Awesome implementation, and I have one change to the static descriptions which will be the same across all sims.

Change the keyboard shortcut's hint in the Scene Summary from:

• "If you need to, check out keyboard shortcuts for this sim." To:
• "If needed, check out keyboard shortcuts for this sim."

[jessegreenberg]

Done in the above commit, changed for sims that currently have a scene summary.