[gnome-control-center] ci: Document review stage

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 5791b9a213b46ec2232bf8483f2a2b8bb3087ca8
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Tue Dec 11 11:21:04 2018 -0200

    ci: Document review stage
    
    [skip-ci]

 .gitlab-ci.yml | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 46cfe83cd..00502d7ca 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -206,6 +206,13 @@ flatpak:
     - gnome-3-.*
     - master@GNOME/gnome-control-center
 
+##
+# Review
+#
+# Stage: review
+#
+# Starts the Flatpak review process.
+##
 review:
   stage: review
   dependencies:
@@ -229,6 +236,13 @@ review:
     - gnome-3-.*
     - master@GNOME/gnome-control-center
 
+##
+# Stop Review
+#
+# Stage: review
+#
+# Stops the Flatpak review process.
+##
 stop_review:
   stage: review
   script: