add update submodules workflow

Author: dragonwocky

.github/workflows/submodules.yml

@@ -0,0 +1,20 @@
+name: 'update submodules'
+
+on:
+  workflow_dispatch:
+
+jobs:
+  sync:
+    name: 'update submodules'
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout repo
+        uses: actions/checkout@v2
+        with:
+          submodules: true
+      - name: pull updates
+        run: |
+          git pull --recurse-submodules
+          git submodule update --remote --recursive
+      - name: commit changes
+        uses: stefanzweifel/git-auto-commit-action@v4

.gitmodules

@@ -1,12 +1,16 @@
 [submodule "api"]
 	path = api
 	url = [email protected]:notion-enhancer/api.git
+	branch = dev
 [submodule "repo"]
 	path = repo
 	url = [email protected]:notion-enhancer/repo.git
+	branch = dev
 [submodule "media"]
 	path = media
 	url = [email protected]:notion-enhancer/media.git
+	branch = main
 [submodule "dep"]
 	path = dep
 	url = [email protected]:notion-enhancer/dep.git
+	branch = main