Add option for Treasure Chest Game key shuffle

[coavins]

This PR adds an option to support the shuffle of the treasure chest game keys. It is found under the TH keys shuffle option. The setting is off by default, and it's off in every preset.

• I added a call to update_items() in init.lua so that it would account for the default setting being "off" and max out my key count by default. No idea what other consequences this has, but it makes this setting work as expected.
• The image files I provided are just placeholders and should be replaced
• Presets should be reviewed for correct default setting
• I did not make the game rooms hintable, this should be verified
• I guessed at how many rooms (and keys) are actually in the treasure chest game, please verify
• I added the key count on a new row in the layout, you may want to put this somewhere else

[coavins]

Moved it to match the position in the OOTR generator and readme: