Update README

Author: thombashi

README.rst

@@ -44,6 +44,51 @@ Features
 * Goes beyond pairs! If/when required can generate n-wise combinations.
 
 
+Usage
+------------
+
+.. code:: python
+    
+    from allpairspy import AllPairs
+
+    parameters = [
+        ["Brand X", "Brand Y"],
+        ["98", "NT", "2000", "XP"],
+        ["Internal", "Modem"],
+        ["Salaried", "Hourly", "Part-Time", "Contr."],
+        [6, 10, 15, 30, 60]
+    ]
+
+    print("PAIRWISE:")
+    for i, parameter in enumerate(AllPairs(parameters)):
+        print("{:2d}: {}".format(i, parameter))
+
+.. code:: 
+
+     0: ['Brand X', '98', 'Internal', 'Salaried', 6]
+     1: ['Brand Y', 'NT', 'Modem', 'Hourly', 6]
+     2: ['Brand Y', '2000', 'Internal', 'Part-Time', 10]
+     3: ['Brand X', 'XP', 'Modem', 'Contr.', 10]
+     4: ['Brand X', '2000', 'Modem', 'Part-Time', 15]
+     5: ['Brand Y', 'XP', 'Internal', 'Hourly', 15]
+     6: ['Brand Y', '98', 'Modem', 'Salaried', 30]
+     7: ['Brand X', 'NT', 'Internal', 'Contr.', 30]
+     8: ['Brand X', '98', 'Internal', 'Hourly', 60]
+     9: ['Brand Y', '2000', 'Modem', 'Contr.', 60]
+    10: ['Brand Y', 'NT', 'Modem', 'Salaried', 60]
+    11: ['Brand Y', 'XP', 'Modem', 'Part-Time', 60]
+    12: ['Brand Y', '2000', 'Modem', 'Hourly', 30]
+    13: ['Brand Y', '98', 'Modem', 'Contr.', 15]
+    14: ['Brand Y', 'XP', 'Modem', 'Salaried', 15]
+    15: ['Brand Y', 'NT', 'Modem', 'Part-Time', 15]
+    16: ['Brand Y', 'XP', 'Modem', 'Part-Time', 30]
+    17: ['Brand Y', '98', 'Modem', 'Part-Time', 6]
+    18: ['Brand Y', '2000', 'Modem', 'Salaried', 6]
+    19: ['Brand Y', '98', 'Modem', 'Salaried', 10]
+    20: ['Brand Y', 'XP', 'Modem', 'Contr.', 6]
+    21: ['Brand Y', 'NT', 'Modem', 'Hourly', 10]
+
+
 Installation
 ------------