doc: make -f Makefile.doc (#2919)

mechanical change: create the manual pages.

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

man/coredns-ready.7

@@ -1,11 +1,11 @@
 .\" Generated by Mmark Markdown Processer - mmark.nl
-.TH "COREDNS-READY" "7" "April 2019" "CoreDNS" "CoreDNS Plugins"
+.TH "COREDNS-READY" 7 "June 2019" "CoreDNS" "CoreDNS Plugins"
 
-.SH NAME
+.SH "NAME"
 .PP
 \fIready\fP - enables a readiness check HTTP endpoint.
 
-.SH DESCRIPTION
+.SH "DESCRIPTION"
 .PP
 By enabling \fIready\fP an HTTP endpoint on port 8181 will return 200 OK, when all plugins that are able
 to signal readiness have done so. If some are not ready yet the endpoint will return a 503 with the
@@ -14,9 +14,11 @@ will not be queried again.
 
 .PP
 Each Server Block that enables the \fIready\fP plugin will have the plugins \fIin that server block\fP
-report readiness into the /ready endpoint that runs on the same port.
+report readiness into the /ready endpoint that runs on the same port. This also means that the
+\fIsame\fP plugin with different configurations (in potentialy \fIdifferent\fP Server Blocks) will have
+their readiness reported as the union of their respective readinesses.
 
-.SH SYNTAX
+.SH "SYNTAX"
 .PP
 .RS
 
@@ -29,14 +31,14 @@ ready [ADDRESS]
 .PP
 \fIready\fP optionally takes an address; the default is \fB\fC:8181\fR. The path is fixed to \fB\fC/ready\fR. The
 readiness endpoint returns a 200 response code and the word "OK" when this server is ready. It
-returns a 503 otherwise.
+returns a 503 otherwise \fIand\fP the list of plugins that are not ready.
 
-.SH PLUGINS
+.SH "PLUGINS"
 .PP
 Any plugin wanting to signal readiness will need to implement the \fB\fCready.Readiness\fR interface by
 implementing a method \fB\fCReady() bool\fR that returns true when the plugin is ready and false otherwise.
 
-.SH EXAMPLES
+.SH "EXAMPLES"
 .PP
 Let \fIready\fP report readiness for both the \fB\fC.\fR and \fB\fCexample.org\fR servers (assuming the \fIwhois\fP
 plugin also exports readiness):