specify cookiecutter branch, use shortcut for github URL

Steve Piercy

2017-06-02 813b7c636a77c0a1a182f9390cfadd0a452c5d2a

 docs/narr/project.rst

@@ -85,7 +85,7 @@

.. code-block:: bash

   $ cookiecutter https://github.com/Pylons/pyramid-cookiecutter-starter
   $ cookiecutter gh:Pylons/pyramid-cookiecutter-starter --checkout 1.8-branch

If prompted for the first item, accept the default ``yes`` by hitting return.