Update demo-deploy-on-g5k.md

demo-deploy-on-g5k.md

 # Deploy a bare-metal on G5k in n steps
 
-## Connected to nantes site 
+The primary way to move around Grid'5000 is using SSH. A [reference page on SSH](https://www.grid5000.fr/w/SSH) is updated and maintained with advanced configuration options that frequent users will find useful.
+
+<img src="https://www.grid5000.fr/mediawiki/images/Grid5000_SSH_access.png" width=80% height=80%>
+
+## Connection to nantes site 
+
+https://www.grid5000.fr/w/Nantes
 
 - direct way through a proxy
   ```bash