emergency-access: Use default instead of mylounge instance name

The mylounge instance name seems confusing.

clanServices/emergency-access/README.md

@@ -4,7 +4,7 @@ This service will automatically set the emergency access password if your system
 
 ```nix
 inventory.instances = {
-  mylounge = {
+  default = {
     module = {
       name = "emergency-access";
       input = "clan-core";