Added a CONTRIBUTING page and linked to it from the README.

Author: Erin Doyle

CONTRIBUTING.md

@@ -0,0 +1,73 @@
+# Contributing to react-a11y
+
+## Setting up the workspace
+
+Before you can submit a Pull Request you'll need to do the following:
+
+1. Fork the repository on GitHub
+
+2. Clone your fork
+
+```bash
+git clone https://github.com/<your_username>/react-a11y.git
+cd react-a11y
+```
+
+3. Install for development
+
+```bash
+npm install
+```
+
+## Workflow
+
+Lint the code:
+
+```bash
+npm run lint
+```
+
+Run the tests:
+
+```bash
+npm run mocha // run tests using mocha only
+npm run karma // run tests using karma only
+npm run test  // run tests using both mocha and karma
+```
+
+Build the code:
+
+```bash
+npm run build
+```
+
+## Making changes
+
+1. Checkout a new branch and name it accordingly to what you intend to do
+
+```bash
+git checkout -b <branch_name>
+```
+
+2. Make your intended changes, being sure to run the tests and lint the code.
+ 
+## Submitting a Pull Request
+
+1. Commit your changes (please make commits small and commit messages descriptive):
+
+```bash
+    git commit -m "..."
+```
+
+2. Push to _your_ github repo:
+```bash
+git push origin <branch_name>
+```
+
+3. Go to the GitHub page and click "New Pull request".
+4. Write a good description of the change.
+
+After sending a pull request, other developers will review and discuss your change. Please address all the comments. Once everything is all right, one of the maintainers will merge your changes in.
+
+## Additional Resources
+* [GitHub pull request help](https://help.github.com/categories/collaborating-with-issues-and-pull-requests/)

README.md

@@ -232,8 +232,12 @@ These are some plans I've dreamt up for `react-a11y`:
     maintenance for me, since poeple can build their own, and it 
     would make `react-a11y` a formidable validation tool.
   - [ ] **create a nice project page** with documentation, because
-    that is what poeple like these days.
+    that is what people like these days.
   - [ ] create filtering options based on rule outputs like `affects`
+  
+## Contributing
+
+Interested in contributing?  Great!  Look here for more info: [CONTRIBUTING.md](https://github.com/romeovs/react-a11y/blob/master/CONTRIBUTING.md).
 
 [react-a11y]:    https://github.com/reactjs/react-a11y
 [eslint]:        http://eslint.org