Update README.md

I replaced "merge requests" by "commits". As far as I notice, merge requests per se don't trigger CI; commits and pushes (which are essentially adding commits) do. This is logical: an MR doesn't create anything new, so there is nothing to test.

doc/ci/quick_start/README.md

@@ -6,7 +6,7 @@ projects.
 GitLab offers a [continuous integration][ci] service. If you
 [add a `.gitlab-ci.yml` file][yaml] to the root directory of your repository,
-and configure your GitLab project to use a [Runner], then each merge request or
+and configure your GitLab project to use a [Runner], then each commit or
 push, triggers your CI [pipeline].
 The `.gitlab-ci.yml` file tells the GitLab runner what to do. By default it runs
@@ -14,8 +14,8 @@ a pipeline with three [stages]: `build`, `test`, and `deploy`. You don't need to
 use all three stages; stages with no jobs are simply ignored.
 If everything runs OK (no non-zero return values), you'll get a nice green
-checkmark associated with the pushed commit or merge request. This makes it
-easy to see whether a merge request caused any of the tests to fail before
+checkmark associated with the commit. This makes it
+easy to see whether a commit caused any of the tests to fail before
 you even look at the code.
 Most projects use GitLab's CI service to run the test suite so that