Add a simple Title Screen to Part 2

[ISSOtm]

This lesson will introduce a title screen. The intent is to introduce separate "scenes", and the transitions between them.

Pressing a certain button on the title screen will begin the game, and a Game Over will kick back to the title screen.

• First, please propose an implementation, and send it in as a draft pull request (see step 6 of this guide for how to do so). (Maintainers can mark it as draft themselves afterwards, so don't worry.)
• The PR will be reviewed by one or more people, and you may have to modify your implementation based on their feedback.
• After a maintainer has greenlit your implementation, you can start writing the tutorial text, which describes the implementation.
• Once the description is fully written, please mark the PR as "ready to review" to signify as much.

[evie-calico]

I think we should do a palette rotate before switching scenes

[ISSOtm]

You must write the code that the explanation will rely on, so you should probably start with that.

[zlago]

so, 'scenes', what about em? is it just .loop: halt, poll input, compare input with PADF_START, then jr z, .loop followed by jp Main, repeat for game over?

[wilkersonrdevon]

Are we wanting something along the lines of part 3 title screen (game states and whatnot), or just loading an image, polling for input, and transitioning into gameplay?

Pressing a certain button on the title screen will begin the game, and a Game Over will kick back to the title screen. Score tracking, and a "Game Over" screen presenting it, should be left as an exercise to the reader.
This entry makes it seem like the latter but I figured I'd check before beginning.