Don't advertise the use of "ci skip" in the CONTRIBUTING guide

Now that we autoscale runner, we don't need to optimize for their usage
anymore. Abusing of "ci skip", for instance for view changes can lead to
broken specs, so let's just not use it!
Signed-off-by: Rémy Coutable <remy@rymai.me>

CONTRIBUTING.md

@@ -311,13 +311,11 @@ request is as follows:
 1. Create a feature branch
 1. Write [tests](https://gitlab.com/gitlab-org/gitlab-development-kit#running-the-tests) and code
 1. Add your changes to the [CHANGELOG](CHANGELOG)
-1. If you are changing the README, some documentation or other things which
-   have no effect on the tests, add `[ci skip]` somewhere in the commit message
-   and make sure to read the [documentation styleguide][doc-styleguide]
+1. If you are writing documentation, make sure to read the [documentation styleguide][doc-styleguide]
 1. If you have multiple commits please combine them into one commit by
    [squashing them][git-squash]
 1. Push the commit(s) to your fork
-1. Submit a merge request (MR) to the master branch
+1. Submit a merge request (MR) to the `master` branch
 1. The MR title should describe the change you want to make
 1. The MR description should give a motive for your change and the method you
    used to achieve it, see the [merge request description format]