Merge branch 'jramsay/web-terminal' into 'master'

Clearly state web terminal is not supported at all on GitLab.com

See merge request gitlab-org/gitlab-ce!23821

doc/ci/interactive_web_terminal/index.md

@@ -6,8 +6,9 @@ Interactive web terminals give the user access to a terminal in GitLab for
 running one-off commands for their CI pipeline.
 
 NOTE: **Note:**
-GitLab.com does not support interactive web terminal at the moment. Please
-follow [this issue](https://gitlab.com/gitlab-org/gitlab-ce/issues/52611) for
+GitLab.com does not support interactive web terminal at the moment – neither
+using shared GitLab.com runners nor your own runners. Please follow
+[this issue](https://gitlab.com/gitlab-org/gitlab-ce/issues/52611) for
 progress. 
 
 ## Configuration