[gnome-user-docs] Small fix in lockdown-single-app-mode

[Petr Kovář <pmkovar src gnome org>]

commit 899081a6a118cb298b38906aa2071b1f09a0c9ed
Author: Petr Kovar <pkovar redhat com>
Date:   Sun Sep 1 21:58:46 2019 +0200

    Small fix in lockdown-single-app-mode

 system-admin-guide/C/lockdown-single-app-mode.page | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/system-admin-guide/C/lockdown-single-app-mode.page 
b/system-admin-guide/C/lockdown-single-app-mode.page
index d967920e..39920dce 100644
--- a/system-admin-guide/C/lockdown-single-app-mode.page
+++ b/system-admin-guide/C/lockdown-single-app-mode.page
@@ -2,7 +2,7 @@
       xmlns:its="http://www.w3.org/2005/11/its";
       type="topic" style="task"
       id="lockdown-single-app-mode">
-     
+
   <info>
     <link type="guide" xref="user-settings#lockdown"/>
     <link type="guide" xref="sundry#session"/>
@@ -101,8 +101,9 @@ RequiredComponents=kiosk-app;gnome-settings-daemon;kiosk-shell;
     <item>
       <p>Create a desktop file for <sys>kiosk-shell</sys> in
       <file>/usr/share/applications/kiosk-shell.desktop</file>, containing the
-      following line:</p>
+      following lines:</p>
 <code>
+[Desktop Entry]
 Exec=gnome-shell --mode=kiosk
 </code>
     </item>