Expand the as-if-foss docs

doc/development/ee_features.md

@@ -26,6 +26,16 @@ setting the [`FOSS_ONLY` environment variable](https://gitlab.com/gitlab-org/git
 to something that evaluates as `true`. The same works for running tests
 (for example `FOSS_ONLY=1 yarn jest`).
 
+## CI pipelines in a FOSS context
+
+By default, merge request pipelines for development run in an EE-context only. If you are
+developing features that differ between FOSS and EE, you may wish to run pipelines in a
+FOSS context as well.
+
+To run pipelines in both contexts, include `RUN AS-IF-FOSS` in the merge request title.
+
+See the [As-if-FOSS jobs](pipelines.md#as-if-foss-jobs) pipelines documentation for more information.
+
 ## Separation of EE code
 
 All EE code should be put inside the `ee/` top-level directory. The

doc/development/pipelines.md

@@ -460,8 +460,8 @@ of the `gitlab-org/gitlab-foss` project. These jobs are only created in the foll
 - Merge requests which include `RUN AS-IF-FOSS` in their title.
 - Merge requests that changes the CI configuration.
 
-The `* as-if-foss` jobs have the `FOSS_ONLY='1'` variable set and gets their EE-specific
-folders removed before the tests start running.
+The `* as-if-foss` jobs are run in addition to the regular EE-context jobs. They have the `FOSS_ONLY='1'` variable
+set and get their EE-specific folders removed before the tests start running.
 
 The intent is to ensure that a change won't introduce a failure once the `gitlab-org/gitlab` project will be synced to
 the `gitlab-org/gitlab-foss` project.