Merge branch 'evn-geosec-docs' into 'master'

Add a security-review page for Geo

Closes #4074

See merge request gitlab-org/gitlab-ee!3729

doc/gitlab-geo/README.md

@@ -75,7 +75,7 @@ internally by the secondary node to record what data has been replicated.
 
 In the secondary nodes there is an additional daemon: Geo Log Cursor.
 
-## Geo Requirements
+## Geo Recommendations
 
 We highly recommend that you install Geo on an operating system that supports
 OpenSSH 6.9 or higher. The following operating systems are known to ship with a
@@ -216,6 +216,10 @@ example:
 
 This message shows that Geo detected that a repository update was needed for project 1.
 
+## Security of GitLab Geo  
+
+Read the [security review](security-review.md) page.
+
 ## Tuning Geo
 
 Read the [GitLab Geo tuning](tuning.md) documentation.