Documentation: Rename submodules.txt to submodules.md

This will help static site generators that can turn Markdown into HTML
but can't easily turn plain text into HTML.

Change-Id: Iabdbbecd0badddbca2221c6164b254ca163555ad
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/25560
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

0 files changed, 0 insertions, 0 deletions