Update the tls documentation (#1061)
Update the tls documentation (#1061)

* Update the tls documentation

* cant test corefile because we dont have pem data

* Add note on client support

jremond/coredns,miekg/coredns,ii/coredns,miekg/coredns,jremond/coredns,johnbelamaric/coredns,yongtang/coredns,chrisohaver/coredns,ii/coredns,coredns/coredns,johnbelamaric/coredns