[Documentation] Better code commenting of macro magic

[VisenDev]

I'm having a difficult time figuring out what exactly these lines are supposed to do, and I'd imagine i'm not the only one. Given that the CLAY macro is crucial to build anything with this library, it would be helpful having some more explanations of what these macros actually do. I've read thru them a few times and I'm still a bit lost.

clay/clay.h

Lines 95 to 113 in 6a9b723

	#define CLAY__ELEMENT_INTERNAL(...) \
	for (\
	CLAY__ELEMENT_DEFINITION_LATCH = (Clay__OpenElement(), __VA_ARGS__, Clay__ElementPostConfiguration(), 0); \
	CLAY__ELEMENT_DEFINITION_LATCH < 1; \
	++CLAY__ELEMENT_DEFINITION_LATCH, Clay__CloseElement() \
	)
	#define CLAY__6_ARGS(a, b, c, d, e, f) a, b, c, d, e, f
	#define CLAY__5_ARGS(a, b, c, d, e) a, b, c, d, e
	#define CLAY__4_ARGS(a, b, c, d) a, b, c, d
	#define CLAY__3_ARGS(a, b, c) a, b, c
	#define CLAY__2_ARGS(a, b) a, b
	#define CLAY__1_ARGS(a) a
	#define CLAY__0_ARGS() Clay__Noop()
	#define CLAY__ARGS_OVERRIDE(_0, _1, _2, _3, _4, _5, _6, NAME, ...) NAME
	// Publicly visible layout element macros -----------------------------------------------------
	#define CLAY(...) CLAY__ELEMENT_INTERNAL(CLAY__ARGS_OVERRIDE("empty", ##__VA_ARGS__, CLAY__6_ARGS, CLAY__5_ARGS, CLAY__4_ARGS, CLAY__3_ARGS, CLAY__2_ARGS, CLAY__1_ARGS, CLAY__0_ARGS)(__VA_ARGS__))

[nicbarker]

Hello 👋
Agree, there is some real trickery going on here that I had a lot of help with, so it would be great for us to document it with a big block comment.

[nicbarker]

Courtesy of some great work from @FintasticMan #119

[nicbarker]

Explanation of the remaining (much smaller) CLAY macro has been added in this commit: a44423a

[VisenDev]

Nice!