Update 2 - Five new cars!

This update adds five new cars, each with unique driving dynamics.

Standard cars:

• Green (easy): Very responsive with low top speed
• Blue (original car, medium): Higher top speed
• Red (hard): Faster acceleration with unlimited top speed

Special cars:

• Yellow: Super fast and agile
• Cyan: Excellent turning
• Magenta: Extreme straight line performance with poor turning

You can switch between cars using Q and E on keyboard, or d-pad left and d-pad right on controller.

This update contains the commits in this pull request: https://github.com/kvu787/DrivingGameV2/pull/3