Update renovate.json (#372)

- update submodules automatically
- set "dependency update" label
- set "line-openapi-update" label for line-openapi updates

#368

renovate.json

@@ -4,5 +4,15 @@
     "config:base"
   ],
   "automerge": true,
-  "platformAutomerge": true
+  "platformAutomerge": true,
+  "git-submodules": {
+    "enabled": true
+  },
+  "labels": [ "dependency upgrade" ],
+  "packageRules": [
+    {
+      "matchPackagePatterns": ["^line-openapi$"],
+      "labels": ["dependency upgrade", "line-openapi-update"]
+    }
+  ]
 }