Use tag name for docker hub (#24)

Co-authored-by: Florian <[email protected]>

Author: 1technophile

.github/workflows/build_docker.yml

@@ -34,4 +34,4 @@ jobs:
           context: .
           platforms: linux/amd64,linux/arm64,linux/386,linux/arm/v7
           push: true
-          tags: theengs/gateway:latest
+          tags: theengs/gateway:${{ github.event.release.tag_name }}