Add transitive dependencies section to Meta-programming anti-pattern

[Gladear]

As discussed in #13762 (comment), I added a "transitive dependencies" section to "Meta-programming anti-patterns". I obviously open to feedback, whether typos or more general remarks about the content of the section. I've tried to keep it simple whilst exposing the problem, linking to mix xref when complexity arises.

This also fixes the documentation of mix xref a bit, since it only stated "runtime dependencies" can cause compile-connected ones, whilst all dependencies are affected.