Re-add zeroconf-manifest-key

Author: bouwew

custom_components/plugwise/manifest.json

@@ -8,5 +8,6 @@
   "iot_class": "local_polling",
   "loggers": ["plugwise"],
   "requirements": ["plugwise==1.1.0"],
-  "version": "0.52.0"
+  "version": "0.52.0",
+  "zeroconf": ["_plugwise._tcp.local."]
 }