I think you also want something like the following.
Also, acme-client.conf.5 has paths like:
domain key /etc/ssl/private/example.com.key
domain certificate /etc/ssl/example.com.crt
instead of:
domain key /etc/ssl/acme/private/example.com.key
domain certificate /etc/ssl/acme/example.com.crt
Index: acme-client.1
===================================================================
RCS file: /cvs/src/usr.sbin/acme-client/acme-client.1,v
retrieving revision 1.11
diff -u -p -u -r1.11 acme-client.1
--- acme-client.1 15 Sep 2016 20:44:24 -0000 1.11
+++ acme-client.1 31 Oct 2016 14:57:22 -0000
@@ -192,6 +192,7 @@ fi
.Ed
.Sh SEE ALSO
.Xr openssl 1 ,
+.Xr acme-client 5 ,
.Xr httpd.conf 5
.Sh STANDARDS
.Rs
