make -f Makefile.doc (#3633)

Preparing a release; don't want to end up with a dirty repo again.
Signed-off-by: Miek Gieben <miek@miek.nl>

man/coredns.1

 .\" Generated by Mmark Markdown Processer - mmark.miek.nl
-.TH "COREDNS" 1 "October 2019" "CoreDNS" "CoreDNS"
+.TH "COREDNS" 1 "January 2020" "CoreDNS" "CoreDNS"
 
 .SH "COREDNS"
 .PP
@@ -58,5 +58,5 @@ Apache License 2.0
 
 .SH "SEE ALSO"
 .PP
-Corefile(5) coredns-k8s_external(7) coredns-erratic(7) coredns-nsid(7) coredns-any(7) coredns-hosts(7) coredns-acl(7) coredns-dnssec(7) coredns-health(7) coredns-grpc(7) coredns-sign(7) coredns-file(7) coredns-root(7) coredns-autopath(7) coredns-auto(7) coredns-clouddns(7) coredns-dnstap(7) coredns-pprof(7) coredns-tls(7) coredns-loadbalance(7) coredns-cache(7) coredns-ready(7) coredns-whoami(7) coredns-bind(7) coredns-loop(7) coredns-import(7) coredns-chaos(7) coredns-template(7) coredns-azure(7) coredns-log(7) coredns-kubernetes(7) coredns-forward(7) coredns-debug(7) coredns-secondary(7) coredns-route53(7) coredns-errors(7) coredns-metrics(7) coredns-reload(7) coredns-rewrite(7) coredns-metadata(7) coredns-etcd(7) coredns-cancel(7) coredns-trace(7).
+Corefile(5) coredns-k8s_external(7) coredns-erratic(7) coredns-nsid(7) coredns-any(7) coredns-hosts(7) coredns-acl(7) coredns-dnssec(7) coredns-health(7) coredns-grpc(7) coredns-sign(7) coredns-file(7) coredns-root(7) coredns-auto(7) coredns-pprof(7) coredns-dnstap(7) coredns-clouddns(7) coredns-bufsize(7) coredns-tls(7) coredns-loadbalance(7) coredns-cache(7) coredns-whoami(7) coredns-bind(7) coredns-loop(7) coredns-import(7) coredns-chaos(7) coredns-template(7) coredns-azure(7) coredns-autopath(7) coredns-log(7) coredns-kubernetes(7) coredns-forward(7) coredns-debug(7) coredns-secondary(7) coredns-route53(7) coredns-transfer(7) coredns-errors(7) coredns-ready(7) coredns-reload(7) coredns-rewrite(7) coredns-metrics(7) coredns-metadata(7) coredns-etcd(7) coredns-cancel(7) coredns-trace(7).