[M] Change in coreboot[main]: Documentation: Improve x86_64

[Benjamin Doron (Code Review)]

Attention is currently required from: Arthur Heymans, Felix Held, Martin L Roth, Patrick Rudolph.

Hello Arthur Heymans, Martin L Roth, Patrick Rudolph, build bot (Jenkins),

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/79160?usp=email

to look at the new patch set (#2).

Change subject: Documentation: Improve x86_64
......................................................................

Documentation: Improve x86_64

* Move to own markdown document
* Better describe current implementation
* Update TODOs

Change-Id: Ia5ba51be629a8c878aad64d3297176457cf8e855
Signed-off-by: Patrick Rudolph 
Signed-off-by: Benjamin Doron 
---
M Documentation/arch/x86/index.md
A Documentation/arch/x86/x86_64.md
2 files changed, 159 insertions(+), 90 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/60/79160/2