Merge pull request #3857 from Lukasa/params-docs

Say that we use a dictionary of strings.

docs/user/quickstart.rst

@@ -57,8 +57,8 @@ Passing Parameters In URLs
 You often want to send some sort of data in the URL's query string. If
 you were constructing the URL by hand, this data would be given as key/value
 pairs in the URL after a question mark, e.g. ``httpbin.org/get?key=val``.
-Requests allows you to provide these arguments as a dictionary, using the
-``params`` keyword argument. As an example, if you wanted to pass
+Requests allows you to provide these arguments as a dictionary of strings,
+using the ``params`` keyword argument. As an example, if you wanted to pass
 ``key1=value1`` and ``key2=value2`` to ``httpbin.org/get``, you would use the
 following code::