Documentation/writing_docs: Document the need for recommonmark

python-recommonmark is need for sphinx to be able to hande the markdown
documentation.

Change-Id: I9513ab4bdc753e0350754d9869239ea833893af9
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/27631
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
1 file changed