Add GitHub Actions workflow for auto-syncing upstream

Author: universalbit-dev

.github/workflows/auto-sync.yml

@@ -0,0 +1,35 @@
+name: Auto Sync with Upstream
+
+on:
+  schedule:
+    - cron: '0 0 * * *' # daily
+  workflow_dispatch:     # allow manual trigger
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - name: Set up git user
+        run: |
+          git config --global user.name 'github-actions[bot]'
+          git config --global user.email 'github-actions[bot]@users.noreply.github.com'
+
+      - name: Add upstream remote and fetch
+        run: |
+          git remote add upstream https://github.com/upstream_owner/upstream_repo.git
+          git fetch upstream
+
+      - name: Merge upstream changes
+        run: |
+          git checkout master
+          git merge upstream/master
+
+      - name: Push changes
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          git push origin master