traefik: add note on migrating from haproxy
traefik: add note on migrating from haproxy

abn/microservices-infrastructure,CiscoCloud/mantl,sehqlr/mantl,huodon/microservices-infrastructure,abn/microservices-infrastructure,huodon/microservices-infrastructure,CiscoCloud/mantl,KaGeN101/mantl,mantl/mantl,KaGeN101/mantl,datascienceinc/mantl,huodon/microservices-infrastructure,abn/microservices-infrastructure,sehqlr/mantl,datascienceinc/mantl,CiscoCloud/microservices-infrastructure,bitium/mantl,CiscoCloud/microservices-infrastructure,mantl/mantl,bitium/mantl,ContainerSolutions/microservices-infrastructure,ContainerSolutions/microservices-infrastructure,huodon/microservices-infrastructure,phnmnl/mantl,huodon/microservices-infrastructure,phnmnl/mantl