Added user guide (#62)

docs/user_guide.rst

@@ -1,2 +1,25 @@
 User Guide
 ==========
+
+FoxPuppet is a library for automating user interactions in Firefox using Selenium.
+This section give some example use cases of FoxPuppet.
+
+Example
+-------
+
+This is an example for setting up FoxPuppet and opening a private window::
+
+    from foxpuppet import FoxPuppet
+    from selenium.webdriver import Firefox
+
+
+    selenium = Firefox()
+    foxpuppet = FoxPuppet(selenium)
+
+    window = foxpuppet.browser.open_window(private=True)
+    selenium.quit()
+
+This example opens first a non-private browser window, then proceeds to open a private browser window.
+Finally it quits via :py:func:`selenium.quit`.
+
+:Note: The initial browser window is automatically assigned to the :py:attr:`browser` attribute and is always available.

foxpuppet/windows/base.py

@@ -36,6 +36,7 @@ def firefox_version(self):
 
     def close(self):
         """Closes the window"""
+
         self.switch_to()
         self.selenium.close()