feat: auto build and publish image on push

.github/workflows/publish-ghcr.yaml

@@ -0,0 +1,19 @@
+name: Build and Publish to Github Container Registry 
+
+on:
+  push
+
+jobs:
+  build_and_publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Login onto ghcr
+        run: |
+          docker login --user maldorne-bot --password ${{ secrets.MALDORNE_BOT_GHCR_TOKEN }} ghcr.io
+      - name: Build image
+        run: |
+          docker build --no-cache . -t ghcr.io/maldorne/mudos:v21.7
+      - name: Publish image
+        run: |
+          docker push ghcr.io/maldorne/mudos:v21.7