Add github action for private to public

Author: bd-jimmy

.github/workflows/sync_to_public.yml

@@ -0,0 +1,25 @@
+name: Sync to Public Repo
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  git-sync:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Private Repo
+        uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+          # This prevents the default GitHub token from overriding your PAT
+          persist-credentials: false 
+
+      - name: Push to Public Mirror
+        env:
+          PUBLIC_TOKEN: ${{ secrets.PUBLIC_REPO_TOKEN }}
+        run: |
+          # Use the 'oauth2' prefix which is often more reliable for fine-grained tokens
+          git remote add public https://oauth2:${PUBLIC_TOKEN}@github.com/Pico-Developer/SecureMR-Samples.git
+          git push public main --force