docs: kernel-docs: reflect that it is community-maintained

Remove and rephrase statements that only make sense if a single author
exclusively would maintain this document, but we would really want to
consider this being a page maintained by the kernel community, as it is
placed in the kernel repository,  and let us hope that more contributors
suggest some more documents.

Further, do some minor word-smithing.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Link: https://lore.kernel.org/r/20220704122537.3407-4-lukas.bulwahn@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>