Update renovate.json

Author: tboerger

renovate.json

@@ -1,5 +1,13 @@
 {
   "extends": [
     "config:base"
+  ],
+  "docker": {
+    "fileMatch": [
+      "/docker/Dockerfile"
+    ]
+  },
+  "labels": [
+    "renovate"
   ]
 }