add testing heading to readme (#373)

* add testing heading to readme

* link readme development section to documentation

* Update README.md

README.md

@@ -78,6 +78,10 @@ In this demonstration, we use a multi-table dataset of 3 million online grocery
 
 For more examples of how to use Featuretools, check out our [demos](https://www.featuretools.com/demos) page.
 
+## Testing & Development
+
+The Featuretools community welcomes pull requests. Instructions for testing and development are avialable [here.](https://docs.featuretools.com/getting_started/install.html#development)
+
 ## Support
 The Featuretools community is happy to provide support to users of Featuretools. Project support can be found in four places depending on the type of question: