docs: Link to canonical requests documentation hosted on "Read the Docs"

CHANGELOG.md

@@ -6,6 +6,8 @@
 
 - Switch to [Zensical for building the documentation](https://zensical.org/) [#62](https://github.com/python-backoff/backoff/pull/62) (from [@edgarrmondragon](https://github.com/edgarrmondragon))
 - Include changelog in the documentation [#65](https://github.com/python-backoff/backoff/pull/65) (from [@edgarrmondragon](https://github.com/edgarrmondragon))
+- Link to canonical `requests` documentation hosted on "Read the Docs" [#67](https://github.com/python-backoff/backoff/pull/67) (from [@edgarrmondragon](https://github.com/edgarrmondragon))
+
 
 ### Internal
 

README.rst

@@ -26,7 +26,7 @@ for asynchronous code.
 Examples
 ========
 
-Since Kenneth Reitz's `requests <http://python-requests.org>`_ module
+Since Kenneth Reitz's `requests <https://requests.readthedocs.io>`_ module
 has become a defacto standard for synchronous HTTP clients in Python,
 networking examples below are written using it, but it is in no way required
 by the backoff module.