MAINTAINERS improv suggestion

[Bagas Sanjaya <bagasdotme@gmail.com>]

Hi Lukas and everyone in linux-doc ML,

Thanks for your work on doc cleanup. However, there's still one thing left:
MAINTAINERS. The patch submitters tips, IMO, need some work.

Here's my notes:

* Nowadays most drivers (especially on embedded architectures like Arm) were
  initially developed out-of-tree, then follows mainline inclusion process
  But the second item read "Try to release a few ALPHA test versions to the
  net. Announce them onto the kernel channel and await results". These
  drivers were submitted not as ALPHA-grade, but near-production grade.

* The fifth item mentioned using `diff -u` to generate patches, however
  since 9f364b605f34e1 ("submitting-patches.rst: presume git will be used"),
  the documentation elsewhere assumed git would be used.

Thanks.

-- 
An old man doll... just what I always wanted! - Clara