Adding a GUI how-to for changing the external network

faq/README.md

@@ -18,6 +18,7 @@ Personal projects can allocate floating IPs from *public-muni-147-251-124* and *
 Group projects can currently allocate floating IPs from *public-cesnet-78-128-251* and *private-muni-10-16-116*.
 IP addresses from *public-muni-147-251-124* allocated by users to group projects are released daily, so we encourage
 using only *public-cesnet-78-128-251* and *private-muni-10-16-116* for group projects.
+Follow instructions at [changing the external network](/network/README.md) in order to change your public network.
 
 ## Issues with network stability in Docker
 OpenStack instances use 1442 bytes MTU (maximum transmission unit) instead of standard 1500 bytes MTU. Instance itself is