all: update documentation, align structs

Probably not going to improve performance but I like seeing powers of two for sizes of structs. Also replaced unsigned short int by uint8_t. 2 vs 1 bytes. Looks neater and is more consistent. And added a warning for it. It impressed me so much I had to. I looked into threading the Lua script but Lua's coroutines are not what I thought they were. Other idea I had was to compile the script once per thread, send each script's function its own piece of objects along with the total and async read the returned objects from each script. Very messy. Won't be a problem to write things in since the threads will access a different portion of objects. Might be too messy. Will see. Thankfully Lua contexts are so much better to use than SDL's "there's no such thing as other threads, you may only ever access SDL functions via its host thread".