factory/locale.conf: mention systemd ownership

This explicitly mentions that comments and empty lines are supported
(and ignored) in /etc/locale.conf. It then adds ownership reference
to the factory default.

factory/templates/locale.conf.in

@@ -1 +1,3 @@
+# This is the fallback locale configuration provided by systemd.
+
 LANG="{{ SYSTEMD_DEFAULT_LOCALE }}"

man/locale.conf.xml

@@ -32,7 +32,8 @@
 
     <para>The basic file format of <filename>locale.conf</filename> is
     a newline-separated list of environment-like shell-compatible
-    variable assignments. It is possible to source the configuration
+    variable assignments, ignoring comments and empty lines.
+    It is possible to source the configuration
     from shell scripts, however, beyond mere variable assignments, no
     shell features are supported, allowing applications to read the
     file without implementing a shell compatible execution
@@ -107,7 +108,9 @@
 
       <para><filename>/etc/locale.conf</filename>:</para>
 
-      <programlisting>LANG=de_DE.UTF-8
+      <programlisting># Custom settings
+
+LANG=de_DE.UTF-8
 LC_MESSAGES=en_US.UTF-8</programlisting>
     </example>