loader.conf: Clarify the default value of timeout.

Author: Edu4rdSHL

man/loader.conf.xml

@@ -121,7 +121,7 @@
         will be stored as an EFI variable in that case, overriding this option.
         </para>
 
-        <para>If set to <literal>menu-hidden</literal> or <literal>0</literal> no menu
+        <para>If set to <literal>menu-hidden</literal> or <literal>0</literal> (the default) no menu
         is shown and the default entry will be booted immediately. The menu can be shown
         by pressing and holding a key before systemd-boot is launched. Setting this to
         <literal>menu-force</literal> disables the timeout while always showing the menu.</para>