Add tier badges

Add Premium tier badges to Geo docs.

doc/administration/geo/glossary.md

@@ -6,7 +6,7 @@ type: howto
 ---
 
 
-# Geo Glossary
+# Geo Glossary **(PREMIUM SELF)**
 
 NOTE:
 We are updating the Geo documentation, user interface and commands to reflect these changes. Not all pages comply with

doc/administration/geo/replication/version_specific_updates.md

@@ -5,7 +5,7 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 type: howto
 ---
 
-# Version-specific update instructions
+# Version-specific update instructions **(PREMIUM SELF)**
 
 Review this page for update instructions for your version. These steps
 accompany the [general steps](updating_the_geo_nodes.md#general-update-steps)

doc/administration/geo/setup/index.md

@@ -5,7 +5,7 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 type: howto
 ---
 
-# Setting up Geo
+# Setting up Geo **(PREMIUM SELF)**
 
 These instructions assume you have a working instance of GitLab. They guide you through: