Set hard-coded rooms order in config file

config.json.example

@@ -1,27 +1,30 @@
 {
-  "web_port": 5443,
+  "app_port": 5443,
   "heos_host": "REPLACE_WITH_HEOS_HOST",
   "heos_port": 1255,
   "zidoo_host": "REPLACE_WITH_ZIDOO_HOST",
   "zidoo_port": 9529,
-  "targets": {
-    "avr": {
-      "label": "Home Cinema",
-      "heos_name": "REPLACE_WITH_EXACT_HEOS_NAME"
-    },
-    "lego_room": {
-      "label": "Lego Room",
-      "heos_name": "REPLACE_WITH_EXACT_HEOS_NAME"
-    },
+  "rooms": {
     "living_room": {
       "label": "Living Room",
       "heos_name": "REPLACE_WITH_EXACT_HEOS_NAME",
       "spotify_name": "REPLACE_ONLY_IF_DIFFERENT_FROM_HEOS_NAME",
-      "in_room_group": "stereo-pair"
+      "in_room_group": "stereo-pair",
+      "order": 1
+    },
+    "avr": {
+      "label": "Home Cinema",
+      "heos_name": "REPLACE_WITH_EXACT_HEOS_NAME",
+      "order": 2
+    },
+    "lego_room": {
+      "label": "Lego Room",
+      "heos_name": "REPLACE_WITH_EXACT_HEOS_NAME",
+      "order": 3
     }
   },
-  "host_key": "avr",
-  "room_keys": ["living_room", "lego_room"],
+  "host_room": "avr",
+  "guest_rooms": ["living_room", "lego_room"],
   "volume_step": 5,
   "spotify_accounts": {
     "account1": "REPLACE_WITH_ACCOUNT_1_NAME",