add workflow for promoting to prod

Signed-off-by: Joshua Silverio <[email protected]>

Author: jsilverio22

.github/workflows/prod-upgrade.yml

@@ -0,0 +1,21 @@
+name: Update Prod
+
+on:
+  workflow_dispatch:
+jobs:
+  copy-main-to-staging:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v2
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Setup crane
+        uses: imjasonh/setup-crane@00c9e93efa4e1138c9a7a5c594acd6c75a2fbf0c
+
+      - name: Copy Main to Staging
+        run: |
+          crane tag ghcr.io/acorn-io/hub:stg prod