Tag docker images with semver+major

Author: janw

.github/workflows/docker-build.yaml

@@ -23,7 +23,8 @@ jobs:
           images: ghcr.io/janw/pi-hole-influx
           tags: |
             type=ref,event=pr
-            type=ref,event=tag
+            type=semver,pattern=v{{major}}
+            type=semver,pattern=v{{version}}
             type=edge,branch=$repo.default_branch
             type=raw,value=latest,enable={{is_default_branch}}