Add a section explaining how the detect feature works and when it should be used. Change-Id: Ife5178d4565e76d0ff436c835c9c47525015c3ed Signed-off-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/67763 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Felix Held <felix-coreboot@felixheld.de>