chore(docs): Add links to help first-time contributors

Invitation: https://twitter.com/dignifiedquire/status/696758773067739136

CONTRIBUTING.md

@@ -15,7 +15,11 @@ If you find a bug in the source code or a mistake in the documentation, you can
 submitting an issue to our [GitHub Repository][github_newissue]. Even better you can submit a Pull Request
 with a fix.
 
+**Working on your first Pull Request?** You can learn how from this *free* series
+[How to Contribute to an Open Source Project on GitHub](egghead_series)
+
 [docs_contributing]: http://karma-runner.github.io/0.13/dev/contributing.html
 [gitter]: https://gitter.im/karma-runner/karma
 [stackoverflow]: http://stackoverflow.com/questions/tagged/karma-runner
 [github_newissue]: https://github.com/karma-runner/karma/issues/new
+[egghead_series]: https://egghead.io/series/how-to-contribute-to-an-open-source-project-on-github

README.md

@@ -1,7 +1,7 @@
 # Karma
 [![js-standard-style](https://img.shields.io/badge/code%20style-standard-brightgreen.svg?style=flat-square)](https://github.com/karma-runner/karma) [![npm version](https://img.shields.io/npm/v/karma.svg?style=flat-square)](https://www.npmjs.com/package/karma) [![npm downloads](https://img.shields.io/npm/dm/karma.svg?style=flat-square)](https://www.npmjs.com/package/karma)
 
-[![Build Status](https://img.shields.io/travis/karma-runner/karma/master.svg?style=flat-square)](https://travis-ci.org/karma-runner/karma) [![Code Climate](https://img.shields.io/codeclimate/github/karma-runner/karma.svg?style=flat-square)](https://codeclimate.com/github/karma-runner/karma) [![Dependency Status](https://img.shields.io/david/karma-runner/karma.svg?style=flat-square)](https://david-dm.org/karma-runner/karma) [![devDependency Status](https://img.shields.io/david/dev/karma-runner/karma.svg?style=flat-square)](https://david-dm.org/karma-runner/karma#info=devDependencies)
+[![Build Status](https://img.shields.io/travis/karma-runner/karma/master.svg?style=flat-square)](https://travis-ci.org/karma-runner/karma) [![Code Climate](https://img.shields.io/codeclimate/github/karma-runner/karma.svg?style=flat-square)](https://codeclimate.com/github/karma-runner/karma) [![PRs Welcome](https://img.shields.io/badge/prs-welcome-brightgreen.svg?style=flat-square)](http://makeapullrequest.com) [![Dependency Status](https://img.shields.io/david/karma-runner/karma.svg?style=flat-square)](https://david-dm.org/karma-runner/karma) [![devDependency Status](https://img.shields.io/david/dev/karma-runner/karma.svg?style=flat-square)](https://david-dm.org/karma-runner/karma#info=devDependencies)
 
 [![Sauce Test Status](https://saucelabs.com/browser-matrix/karmarunnerbot.svg)](https://saucelabs.com/u/karmarunnerbot)
 

docs/dev/01-contributing.md

@@ -1,5 +1,7 @@
 pageTitle: Contributing to Karma
 
+**Working on your first Pull Request?** You can learn how from this *free* series
+[How to Contribute to an Open Source Project on GitHub](egghead_series)
 
 You wanna contribute to Karma? That is truly great!
 Here are some tips to get you started...
@@ -52,3 +54,4 @@ You just do it. There is no test to pass ;-)
 [Stack Overflow]: http://stackoverflow.com/questions/tagged/karma-runner
 [`docs/`]: https://github.com/karma-runner/karma/tree/master/docs
 [Maintaining Karma]: ./maintaining.html
+[egghead_series]: https://egghead.io/series/how-to-contribute-to-an-open-source-project-on-github