Change the wording from "these will fail" to "this must be followed" which is
easier to understand. And add the requirement for uppercase hex numbers as
enforced since c412924003.
Related #568
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Make the headers valid markdown and reword/reformat a few other things
to make it clearer and easier to read.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
