Added Geo to Changelog and removed some limitations from documentation

CHANGELOG-EE

@@ -14,6 +14,10 @@ v 8.6.0 (unreleased)
   - [Elastic] More accurate as_indexed_json (More stable database indexer)
   - [Elastic] Fix: Don't index newly created system messages and awards
   - [Elastic] Fixed exception on branch removing
+  - GitLab Geo: OAuth authentication
+  - GitLab Geo: Wiki synchronization
+  - GitLab Geo: ReadOnly Middleware improvements
+  - GitLab Geo: SSH Keys synchronization
 
 v 8.5.8
   - GitLab Geo: Documentation

doc/administration/gitlab-geo/README.md

 # GitLab Geo
 
 > **Note:**
-This feature was introduced in GitLab 8.5 EE.
+This feature was introduced in GitLab 8.5 EE as Alpha.
+We recommend you use with at least GitLab 8.6 EE.
 
 GitLab Geo allows you to replicate your GitLab instance to other geographical
 locations as a read-only fully operational version.
@@ -65,13 +66,9 @@ there are a few things to consider:
 
 ## Current limitations
 
-- The secondary node cannot be used for browsing
 - You cannot push code to secondary nodes
 - Git LFS is not supported yet
 - Git Annex is not supported yet
-- Wiki's are not being replicated yet
-- Git clone from secondaries by HTTP/HTTPS only (ssh-keys aren't being
-  replicated yet)
 
 ## Frequently Asked Questions