Merge branch 'docs/update-complex-rule-clauses' into 'master'

Improve example description text for complex rule clauses.

See merge request gitlab-org/gitlab!48886

doc/ci/yaml/README.md

@@ -1417,7 +1417,7 @@ same rule.
 
 In the following example:
 
-- If the `Dockerfile` file or any file in `/docker/scripts` has changed, and var=blah,
+- If the `Dockerfile` file or any file in `/docker/scripts` has changed, and `$VAR` == "string value",
   then the job runs manually
 - Otherwise, the job isn't included in the pipeline.