mlib contains a lot of "macro magic". While this is very useful, it can be a bit hard to grok for those less familiar with macro metaprogramming.

Currently, almost all macros are in a very large config.h header. It would be beneficial for maintainability to:

1. Split macro metaprogramming macros into different files to increase discoverability.
2. Heavily inline-document the purpose and behavior of metaprogramming macros, to increase the bus factor around them.