Move the contributing guide into its own file

Author: dmtucker

CONTRIBUTING.rst

@@ -0,0 +1,32 @@
+Contributing
+============
+
+Contributions are very welcome. Tests can be run with `tox <https://tox.readthedocs.io/en/latest/>`_.
+Please ensure the coverage at least stays the same before you submit a pull request.
+
+.. image:: https://travis-ci.org/dbader/pytest-mypy.svg?branch=master
+    :target: https://travis-ci.org/dbader/pytest-mypy
+    :alt: See Build Status on Travis CI
+
+Development Environment Setup
+-----------------------------
+
+Here's how to install pytest-mypy in development mode so you can test your changes locally:
+
+.. code-block:: bash
+
+    tox --devenv venv
+    venv/bin/pytest --mypy test_example.py
+
+How to publish a new version to PyPI
+------------------------------------
+
+Push a tag, and Travis CI will publish it automatically.
+To publish manually:
+
+.. code-block:: bash
+
+    python -m venv venv
+    venv/bin/pip install pep517 twine
+    venv/bin/python -m pep517.build .
+    venv/bin/twine upload dist/*

README.rst

@@ -1,18 +1,12 @@
 pytest-mypy
 ===================================
 
-.. image:: https://travis-ci.org/dbader/pytest-mypy.svg?branch=master
-    :target: https://travis-ci.org/dbader/pytest-mypy
-    :alt: See Build Status on Travis CI
+Mypy static type checker plugin for pytest
 
 .. image:: https://img.shields.io/pypi/v/pytest-mypy.svg
-   :target: https://pypi.python.org/pypi/pytest-mypy
+   :target: https://pypi.org/project/pytest-mypy/
    :alt: See Latest Release on PyPI
 
-Mypy static type checker plugin for pytest
-
-----
-
 Features
 --------
 
@@ -54,32 +48,6 @@ You can restrict your test run to only perform mypy checks and not any other tes
 
     py.test --mypy -m mypy test_*.py
 
-Contributing
-------------
-Contributions are very welcome. Tests can be run with `tox`_, please ensure
-the coverage at least stays the same before you submit a pull request.
-
-Development Environment Setup
------------------------------
-Here's how to install pytest-mypy in development mode so you can test your
-changes locally:
-
-.. code-block:: bash
-
-    $ pyvenv venv
-    $ source venv/bin/activate
-    $ python setup.py develop
-    $ venv/bin/py.test --mypy example_test.py
-
-How to publish a new version to PyPI
-------------------------------------
-
-.. code-block:: bash
-
-    $ pip install twine wheel
-    $ python setup.py sdist bdist_wheel
-    $ twine upload dist/*
-
 License
 -------
 
@@ -100,7 +68,6 @@ https://github.com/dbader/pytest-mypy
 
 .. _`MIT`: http://opensource.org/licenses/MIT
 .. _`file an issue`: https://github.com/dbader/pytest-mypy/issues
-.. _`tox`: https://tox.readthedocs.io/en/latest/
 .. _`pip`: https://pypi.python.org/pypi/pip/
 .. _`PyPI`: https://pypi.python.org/pypi
 .. _`mypy`: http://mypy-lang.org/