[submodule] update listener

Author: wanomaniac

.github/workflows/submodule_sender.yaml

@@ -0,0 +1,13 @@
+- name: Notify root repository
+  run: |
+    curl -X POST \
+      -H "Authorization: token ${{ secrets.BORA_ROOT_PAL }}" \
+      -H "Accept: application/vnd.github.v3+json" \
+      https://api.github.com/repos/boradevelopment/bora/dispatches \
+      -d '{
+        "event_type": "update_submodule",
+        "client_payload": {
+          "repo": "${{ github.repository }}",
+          "branch": "${{ github.ref_name }}"
+        }
+      }'