More Details for the configuration of the gitlab container registry

Hey,

thanks for releasing this feature. But I got a little bit confused because i don't know how exactly setup the container registry from source. And the Documtation says that you need to install git docker registry by your self.

I want to ask if im on the correct way.

Here is my gitlab.yml

loglevel: debug                                                                                                                                                                                                 
storage:                                                                                                                                                                                                        
   filesystem:                                                                                                                                                                                                   
     rootdirectory: /data                                                                                                                                                                                        
   delete:                                                                                                                                                                                                       
     enabled: true                                                                                                                                                                                               
 http:                                                                                                                                                                                                           
   addr: 0.0.0.0:5000                                                                                                                                                                                            
   tls:                                                                                                                                                                                                          
     certificate: /certs/docker-registry.crt                                                                                                                                                                     
     key:  /certs/docker-registry.key                                                                                                                                                                            
 auth:                                                                                                                                                                                                           
    token:                                                                                                                                                                                                       
      realm: <mycontainerregistrydomin>/jwt/auth                                                                                                                                                                 
      service: container_registry                                                                                                                                                                                
      issuer: gitlab-issuer                                                                                                                                                                                      
      rootbundlecert: /certs/docker-registry.crt