add docker action

.github/workflows/docker.yml

@@ -0,0 +1,37 @@
+# github action to Build and publish Docker image
+
+name: Docker
+
+on:
+    push:
+      branches: [ master ]
+
+jobs:
+    build:
+        name: Build
+        runs-on: ubuntu-latest
+        steps:
+        - name: Set up Go 1.x
+          uses: actions/setup-go@v4
+
+        - name: Check out code into the Go module directory
+          uses: actions/checkout@v2
+
+        - name: Build
+          run: go get github.com/mat/besticon/...
+
+        - name: Login to Docker Hub
+          uses: docker/login-action@v3
+          with:
+            username: ${{ vars.DOCKERHUB_USERNAME }}
+            password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+        - name: Build Docker image
+          run: docker build --platform=linux/amd64 -t matthiasluedtke/iconserver:latest .
+
+
+        # - name: Tag Docker image
+        # run: docker tag besticon "${{ secrets.DOCKER_USERNAME }}/besticon"
+
+        - name: Push Docker image
+          run: docker push "${{ vars.DOCKERHUB_USERNAME }}/besticon"