Add Gitea Actions workflow to build and push docker image

.github/workflows/docker-build.yml

@@ -0,0 +1,32 @@
+name: Build & Push Docker Image to GHCR
+
+on:
+  push:
+    branches: [master]
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: kroonk/mischlabs
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ secrets.GHCR_USERNAME }}
+          password: ${{ secrets.GHCR_TOKEN }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: |
+            ghcr.io/kroonk/mischlabs:latest
+            ghcr.io/kroonk/mischlabs:${{ github.sha }}