Added spinning keys as placeable objects in the map image

I modeled this key in blender and rendered out eight frames of it spinning to create this texture atlas. The atlas is pulled from based on the GameTime.

Loading keys into memory from the map proved to be quite a challenge. When initializing the map, the shader reads the map texture for any pixels with opacity 150 and treats them as keys, loading them and their data into a few rows in memory. The data stored and updated along with them is: Their coordinates on the map, their colors, their distance offset from the player, and their rotational offset from the player. Using this data, I created a render pass after the map renderer that adds these in.

Next will be a pickup system so they can be used to unlock doors. The player inventory system is probably gonna suuuuuuck to make.