Add contributing guidelines

CONTRIBUTING.rst

@@ -0,0 +1,24 @@
+Contributing
+------------
+
+We love contributions! These guidelines will help make sure we can get your
+contributions merged as quickly as possible:
+
+1. Write `good commit messages`__!
+2. If you want to add a new feature, talk to us on the `mailing list`__ or
+   `IRC`__ first. We might already have plans, or be able to offer some advice.
+3. Make sure your code passes the tests that ImageKit already has. To run the
+   tests, use ``make test``. This will let you know about any errors or style
+   issues.
+4. While we're talking about tests, creating new ones for your code makes it
+   much easier for us to merge your code quickly. ImageKit uses nose_, so
+   writing tests is painless. Check out `ours`__ for examples.
+5. It's a good idea to do your work in a branch; that way, you can work on more
+   than one contribution at a time without making them interdependent.
+
+
+__ http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html
+__ https://groups.google.com/forum/#!forum/django-imagekit
+__ irc://irc.freenode.net/imagekit
+.. _nose: https://nose.readthedocs.org/en/latest/
+__ https://github.com/jdriscoll/django-imagekit/tree/develop/tests

README.rst

@@ -295,3 +295,13 @@ even Django—to contribute either: ImageKit's processors are standalone classes
 that are completely separate from the more intimidating internals of Django's
 ORM. If you've written a processor that you think might be useful to other
 people, open a pull request so we can take a look!
+
+You can also check out our list of `open, contributor-friendly issues`__ for
+ideas.
+
+Check out our `contributing guidelines`__ for more information about pitching in
+with ImageKit.
+
+
+__ https://github.com/jdriscoll/django-imagekit/issues?labels=contributor-friendly&state=open
+__ https://github.com/jdriscoll/django-imagekit/blob/master/CONTRIBUTING.rst