docs(contrib): Add makeapullrequest.com links

Author: Kent C. Dodds

CONTRIBUTING.md

@@ -29,6 +29,8 @@ with a link to a jsbin that demonstrates the issue with [issue.angular-formly.co
 
 ## Pull Requests
 
+**Working on your first Pull Request?** You can learn how from this *free* series [How to Contribute to an Open Source Project on GitHub](https://egghead.io/series/how-to-contribute-to-an-open-source-project-on-github)
+
 ‼️‼️‼️  👉**Please follow our commit message conventions** even if you're making a small change! This repository follows the
 [How to Write an Open Source JavaScript Library](https://egghead.io/series/how-to-write-an-open-source-javascript-library)
 series on egghead.io (by yours truly). See

README.md

@@ -14,6 +14,8 @@ Links:
 [![egghead.io lessons](https://img.shields.io/badge/egghead-lessons-blue.svg?style=flat-square)](https://egghead.io/playlists/advanced-angular-forms-with-angular-formly)
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/formly-js/angular-formly?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![semantic-release](https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg?style=flat-square)](https://github.com/formly-js/angular-formly/releases)
+[![PRs Welcome](https://img.shields.io/badge/prs-welcome-brightgreen.svg?style=flat-square)](http://makeapullrequest.com)
+
 
 angular-formly is an AngularJS module which has a directive to help customize and render JavaScript/JSON configured forms.
 The `formly-form` directive and the `formlyConfig` service are very powerful and bring unmatched maintainability to your