Change in coreboot[master]: Documentation: Add proposal to allow enabling serial console with a flag

[Furquan Shaikh (Code Review)]

Attention is currently required from: Paul Menzel, Stefan Reinauer, Julius Werner, Arthur Heymans.
Furquan Shaikh has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/54385 )

Change subject: Documentation: Add proposal to allow enabling serial console with a flag
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Patch Set 4: Code-Review+1

(1 comment)

File Documentation/technotes/2021-05-selectable-serial-console.md:

https://review.coreboot.org/c/coreboot/+/54385/comment/62866c1b_6a7867e3 
PS4, Line 127: To avoid adding complexity in the bootblock, bootblock is exempt from
             : this: When enabling this mode, bootblock stage code will not send data
             : to serial for performance reason
Just to ensure I understand this correctly: 
1. bootblock will default to console enabled if it's compiled in.
2. If Kconfig to disable the default is set, bootblock will default to console disabled without looking at the CBFS file. All other stages differ from bootblock i.e. they check for the flag in CBFS file if Kconfig is set.

Is that correct?