[LTP] [PATCH v1] doc: introduce sphinx extlinks

[Petr Vorel]

Hi Andrea,

Thanks a lot, merged!

I'm a bit disappointed that such simple thing as code formatting part of the
link (or whole link) is not possible, but it's a detail. Having links on single
place is an improvement.

NOTE: I still need to trigger doc build manually.

...
> +++ b/doc/developers/test_case_tutorial.rst
> @@ -627,9 +627,8 @@ again on the hard-link, then ``stat`` the file".

>  Because we are now opening a file, we need a ``cleanup`` function to close the
>  file descriptors. We have to manually close the files to ensure the temporary
> -directory is deleted by the test harness (see the
> -https://github.com/linux-test-project/ltp/wiki/Test-Writing-Guidelines[test
> -writing guidelines] for details).
> +directory is deleted by the test harness (see the test writing guidelines for
> +details).

I dared to fix this as a link (in a separate commit):

directory is deleted by the test harness (see :doc:`writing_tests` for details).

Kind regards,
Petr