add ghcr publish workflow.

.github/workflows/publish.yml

@@ -0,0 +1,26 @@
+name: 2 - Publish
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  ghcr_publish:
+    name: Publish Images on GHCR
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v3
+      - name: login to ghcr
+        uses: docker/login-action@v2
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: publish mdtranslator
+        uses: docker/build-push-action@v3
+        with:
+          context: .
+          push: true
+          tags: ghcr.io/gsa/mdtranslator:latest