Fix acl page (#3626)

* Fix acl page

It must have a Name section.

Fixes: https://github.com/coredns/coredns.io/issues/177Signed-off-by: Miek Gieben <miek@miek.nl>

* generate
Signed-off-by: Miek Gieben <miek@miek.nl>

man/coredns-acl.7

 .\" Generated by Mmark Markdown Processer - mmark.miek.nl
 .TH "COREDNS-ACL" 7 "January 2020" "CoreDNS" "CoreDNS Plugins"
 
+.SH "NAME"
 .PP
 \fIacl\fP - enforces access control policies on source ip and prevents unauthorized access to DNS servers.
 

plugin/acl/README.md

 # acl
 
+## Name
+
 *acl* - enforces access control policies on source ip and prevents unauthorized access to DNS servers.
 
 ## Description
@@ -76,4 +78,3 @@ If monitoring is enabled (via the _prometheus_ plugin) then the following metric
 - `coredns_request_allow_count_total{server}` - counter of DNS requests being allowed.
 
 The `server` and `zone` labels are explained in the _metrics_ plugin documentation.
-