Add map properties for federation

maps/main.json

@@ -649,6 +649,17 @@
  "nextlayerid":55,
  "nextobjectid":1,
  "orientation":"orthogonal",
+ "properties":[
+        {
+         "name":"apiUrl",
+         "type":"string",
+         "value":"https:\/\/world.chaosflux.de"
+        }, 
+        {
+         "name":"jitsiUrl",
+         "type":"string",
+         "value":"meet.hasi.it"
+        }],
  "renderorder":"right-down",
  "tiledversion":"1.4.3",
  "tileheight":32,