add screenshots for pavucontrol and xfburn

source/3/3.3/3.3.10/pavucontrol.rst

@@ -10,6 +10,11 @@ Description
  you to redirect a playback stream to another output device without
  interrupting playback
 
+Screenshot
+----------
+.. image::
+   :width:80%
+ 
 Version
 -------
  Lubuntu ships with version 3.0-4
@@ -17,3 +22,4 @@ Version
 How to Launch
 -------------
 To launch pulse audio volume control in the bottom right of the panel there is an icon that looks like a speaker right click and on the menu click sound settings or run pavucontrol from the command line.  
+

source/3/3.3/3.3.11/xfburn.rst

@@ -9,6 +9,11 @@ Version
 -------
 Lubuntu ships with version 0.5.5 of xfburn.
 
+Screenshot
+----------
+.. image::xfburn.png
+   :width: 80%
+
 How to launch
 -------------
 Go to the menu > Sound and video > xfburn. It also has an icon that looks like a cd disk.