chore: opt-in to Git submodule updates (#16)

chore: opt-in to Git Submodule updates

Author: p5

.github/renovate.json5

@@ -22,5 +22,8 @@
     ],
     "dockerfile": {
         "enabled": false
+    },
+    "git-submodules": {
+        "enabled": true
     }
 }