Add an example of varnishd -a /uds usage.

And remove the last XXX from the docs.

doc/sphinx/whats-new/upgrading-6.0.rst

@@ -4,9 +4,6 @@
 Upgrading to Varnish 6.0
 %%%%%%%%%%%%%%%%%%%%%%%%
 
-XXX: Most important change first
-================================
-
 .. _upd_6_0_uds_acceptor:
 
 Unix domain sockets as listen addresses
@@ -18,6 +15,10 @@ begins with ``/`` (see varnishd :ref:`ref-varnishd-options`)::
 
   -a [name=][address][:port][,PROTO][,user=<user>][,group=<group>][,mode=<mode>]
 
+For example::
+
+  varnishd -a /path/to/listen.sock,PROXY,user=vcache,group=varnish,mode=660
+
 That means that an absolute path must always be specified for the
 socket file.  The socket file is created when Varnish starts, and any
 file that may exist at that path is unlinked first. You can use the