Add several documents to the development-process ReST book.

As we don't want renames, use symlinks instead, keeping those
documents on their original place.
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

As we'll type this a lot, after adding CodingStyle & friends,
let's rename the directory name to a shorter one.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

Now that the files at Documentation/development-process/
were converted to ReST, make create a book at Sphinx.

As we'll have other books related to the development process,
we'll add it as a sub-book.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>