kernel-doc: Update "cross-referencing from rST" section to use automarkup

Update text and examples in the "Cross-referencing from
reStructuredText" section to reflect that no additional syntax is needed
anymore.

Signed-off-by: Nícolas F. R. A. Prado <nfraprado@protonmail.com>
Link: https://lore.kernel.org/r/20200903005747.3900333-3-nfraprado@protonmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Nícolas F. R. A. Prado 2020-09-03 00:58:26 +00:00 • committed by Jonathan Corbet
commit 7c8b9e3000