updated to point to the contribution document.

Author: cktricky

README.md

@@ -136,7 +136,7 @@ Alternatively, you can run MailCatcher in the foreground by running `mailcatcher
 
 ## Contributing
 
-As changes are made to the application, the Capybara RSpecs can be used to verify that the vulnerabilities in the application are still intact. To use them in this way, and have them change to `pending` instead of `fail`, set the `RAILSGOAT_MAINTAINER` environment variable.
+Please see our [contribution document](./CONTRIBUTING.md) to learn more. Additionally, note that as changes are made to the application, the Capybara RSpecs can be used to verify that the vulnerabilities in the application are still intact. To use them in this way, and have them change to `pending` instead of `fail`, set the `RAILSGOAT_MAINTAINER` environment variable.
 
 Conversion to the OWASP Top Ten 2013 completed in November, 2013.