add build+push workflow

.github/workflows/build-and-push.yml

@@ -0,0 +1,25 @@
+name: Build image and push
+
+on:
+    push:
+        branches: [main]
+
+jobs:
+    build-and-push:
+        runs-on: [ubuntu-latest]
+        steps:
+            - uses: actions/checkout@v4
+            - name: Set up QEMU
+              uses: docker/setup-qemu-action@v3
+            - name: Set up Docker Buildx
+              uses: docker/setup-buildx-action@v3
+            - name: Login to Dockerhub
+              uses: docker/login-action@v3
+              with:
+                username: ${{ secrets.DOCKERHUB_USERNAME }}
+                password: ${{ secrets.DOCKERHUB_TOKEN }}
+            - name: Build and push
+              uses: docker/build-push-action@v5
+              with:
+                push: true
+                tags: codesmithtech/http-auth-proxy:latest