Fix typo in package-finding.rst
@@ -74,7 +74,7 @@ instantiate ``PackageFinder`` only once for the whole pip invocation. In
fact, pip creates this ``PackageFinder`` instance when command options
are first parsed.
-With the excepton of :ref:`pip list`, each of the above commands is
+With the exception of :ref:`pip list`, each of the above commands is
implemented as a ``Command`` class inheriting from ``RequirementCommand``
(for example :ref:`pip download` is implemented by ``DownloadCommand``), and
the ``PackageFinder`` instance is created by calling the
