docs: Document cross-referencing between documentation pages

The syntax to cross-reference between documentation pages wasn't
documented anywhere.

Document the cross-referencing using the new automarkup for
Documentation/... and also Sphinx's doc directive for using relative
paths.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@protonmail.com>
Link: https://lore.kernel.org/r/20200911133339.327721-4-nfraprado@protonmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Nícolas F. R. A. Prado 2020-09-11 13:34:46 +00:00 • committed by Jonathan Corbet
commit c170f2eb96