README.rst: use tuples in description and examples

Author: orlitzky

README.rst

@@ -14,7 +14,7 @@ of this package is to make them available through a generic python
 interface. The package consists of a single module containing a single
 function that returns a dict of dicts, ``conway_polynomials.database()``.
 The dictionary's format is ``{p => {n => coefficients}}``, where ``p``
-represents your prime and ``n`` your degree. The list of coefficients
+represents your prime and ``n`` your degree. The tuple of coefficients
 is returned in ascending order; that is, the first coefficient (at
 index zero) is for the constant (degree zero) term.
 
@@ -36,13 +36,13 @@ degree n=5::
   >>> import conway_polynomials
   >>> cpdb = conway_polynomials.database()
   >>> cpdb[2][5]
-  [1, 0, 2, 0, 0, 5]
+  (1, 0, 2, 0, 0, 5)
 
 The result is cached, so subsequent computations should be fast even
 if you call the function again::
 
   >>> conway_polynomials.database()[5][5]
-  [3, 4, 0, 0, 0, 1]
+  (3, 4, 0, 0, 0, 1)
 
 Testing
 =======