Change in coreboot[master]: Documentation: Codify some guidelines for headers and chain-including

[Martin Roth (Code Review)]

Attention is currently required from: Julius Werner.
Martin Roth has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/50247 )

Change subject: Documentation: Codify some guidelines for headers and chain-including
......................................................................

Patch Set 2:

(1 comment)

File Documentation/coding_style.md:

https://review.coreboot.org/c/coreboot/+/50247/comment/ac3d0f57_a73d8357 
PS2, Line 850: Excepted from
             : this are certain headers that intentionally chain-include other headers
             : which logically belong to them and are just factored out into a separate
             : location for implementation or organizatory reasons.
> Maybe we want to build a list of these allowed chained headers to head off any arguments? What's log […]

Oh, I had missed the comments on patch 1 saying the same thing.