Make a complete introduction focussing on the enterprise, closes #70

source/index.html

@@ -12,7 +12,9 @@ suppress_header: true
         
         <div class="col-sm-12 col-md-12 text-left">
           <p class="text-center">
-            GitLab offers git repository management, code reviews, issue tracking and wiki's. You can install it on-premise and it fully integrates with your LDAP server.
+            GitLab offers git repository management, code reviews, issue tracking, activity feeds and wiki's.
+            Enterprises install GitLab on-premise and connect it with LDAP and Active Directory servers for secure authentication and authorization.
+            A single GitLab server can handle more than 25,000 users but it is also possible to create a high availability setup with a warm standby server.
           </p>
           <div class="landing-button">