added toml.dump example to Quick Tutorial (#301)

README.rst

@@ -112,6 +112,33 @@ corresponding TOML-formatted data.
   ip = "10.0.0.2"
   dc = "eqdc10"
 
+*toml.dump* takes a dictionary and a file descriptor and returns a string containing the
+corresponding TOML-formatted data.
+
+.. code:: pycon
+
+  >>> with open('new_toml_file.toml', 'w') as f:
+  ...     new_toml_string = toml.dump(parsed_toml, f)
+  >>> print(new_toml_string)
+  title = "TOML Example"
+  [owner]
+  name = "Tom Preston-Werner"
+  dob = 1979-05-27T07:32:00Z
+  [database]
+  server = "192.168.1.1"
+  ports = [ 8001, 8001, 8002,]
+  connection_max = 5000
+  enabled = true
+  [clients]
+  data = [ [ "gamma", "delta",], [ 1, 2,],]
+  hosts = [ "alpha", "omega",]
+  [servers.alpha]
+  ip = "10.0.0.1"
+  dc = "eqdc10"
+  [servers.beta]
+  ip = "10.0.0.2"
+  dc = "eqdc10"
+
 For more functions, view the API Reference below.
 
 Note