better contributor guidelines

CONTRIBUTING.md

@@ -1,9 +1,14 @@
-### Common Issues
+### Troubleshooting
 
-* Check that you're using at least Ansible 2.1
+* Check that you installed all the dependencies with pip and have Ansible 2.1+
 * If installing to a local server, use a fresh install of Ubuntu 16.04
+
+### Filing New Issues
+
 * Please review the [FAQ](https://github.com/trailofbits/algo#faq)
+* Please include the full output from your terminal window if appropriate
 
-### Coding Guidelines
+### Pull Requests
 
-* Please review any Pull Requests with [ansible-lint](https://github.com/willthames/ansible-lint)
+* Run [ansible-lint](https://github.com/willthames/ansible-lint) on any new ansible scripts
+* Run [shellcheck](https://github.com/koalaman/shellcheck) on any new shell scripts