Randomize start position/direction

[Hpmason]

The start position/direction are hard coded in main.rs

gba-dvd/src/main.rs

Lines 70 to 71 in e641f19

	let mut x_dir = Direction::RIGHT;
	let mut y_dir = Direction::UP;

gba-dvd/src/main.rs

Lines 73 to 74 in e641f19

	// Size should be 64x48 (from top left), but takes up a full 64x64 sprite
	let mut dvd_obj = Obj::new(40, 30, 64, 48);

^ position (40, 30)

Possible ways to randomize this include:

• Each time the game boots, save a randomly generated value to a save file. On boot, we can use that value as the starting seed.
  • Each load will be randomized
• Use RTC (Real Time Clock) as starting seed
  • Therefore the starting values will also be randomized and not determined by the previous iteration of the game
  • While this is the nice way to randomize this, it will not work any flashcards without a RTC component