Add how to open a new tab and view history in firefox

source/2/2.1/2.1.1/firefox.rst

@@ -17,10 +17,14 @@ Firefox has features of other web browsers and its own ones, such as:
  - Advanced customization with about:config
  - Open source
 
-Usage/Screenshots
+Screenshot
-----------------------
+--------------
 .. image:: firefox-screenshot.png
    :width: 80%
+Useage
+------
+To open a new tab in firefox press the plus button on the right of the tab bar. To view your browsing history press the button that looks like a stack of books with the last one at the end the third item down will show you history.  
+
 
 Version
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