Merge branch 'docs-update-and-move-the-netdev-faq'

Jakub Kicinski says:

====================
docs: update and move the netdev-FAQ

A section of documentation for tree-specific process quirks had
been created a while back. There's only one tree in it, so far,
the tip tree, but the contents seem to answer similar questions
as we answer in the netdev-FAQ. Move the netdev-FAQ.

Take this opportunity to touch up and update a few sections.

v3: remove some confrontational? language from patch 7
v2: remove non-git in patch 3
    add patch 5
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>