chore: fix container labels

This addresses issues faced when trying to publish conform as a GitHub action.

Signed-off-by: Andrew Rynhard <[email protected]>

Dockerfile

@@ -36,10 +36,12 @@ FROM alpine:3.9 as ca-certificates
 RUN apk add --update --no-cache ca-certificates
 
 FROM scratch AS image
-LABEL com.github.actions.name="Conform"
-LABEL com.github.actions.description="Policy enforcement for your pipelines."
-LABEL com.github.actions.icon="shield"
-LABEL com.github.actions.color="yellow"
+LABEL "com.github.actions.name"="Conform Action"
+LABEL "com.github.actions.description"="Policy enforcement for your pipelines."
+LABEL "com.github.actions.icon"="check-circle"
+LABEL "com.github.actions.color"="black"
+LABEL "repository"="https://github.com/talos-systems/conform.git"
+LABEL "maintainer"="Andrew Rynhard <[email protected]>"
 COPY --from=ca-certificates /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 COPY --from=build /conform-linux-amd64 /conform
 ENTRYPOINT [ "/conform" ]