Hold brake to start car

[smit-happens]

End goal

Have the driver hold the brake pedal down when entering the precharge (or driving?) stage to proceed

Relevant Info/Links

figure out where exactly this will go

[atokosch]

Idea: If the driver isn't pressing the brake when we want them to, we let me know on the GLCD and it will display a message like "Press brake before initiating precharge..., etc"
Also, will we want to make sure that the brake is pressed like 50% of the way so that the brake is definitely engaged? - Assuming we have the ability to do this, which I think we do (please correct me if I am wrong).
Thoughts? @smit-happens @PatHock