config.yml

---
Name: app
After: 'framework/*','cms/*'
---

MySQLDatabase:
  connection_charset: utf8
SiteTree:
  nested_urls: true
GDBackend:
  default_quality: 100
Upload:
  uploads_folder: uploads
LeftAndMain:
  application_link: /
SiteTree:
  extensions:
    - PromoFeatureExtension
    - MarketoExtraPermissions
    - Localization
    - Localization_SiteTree
    - LocalizeValues
    - VersionedRelationships
    - TranslationProjectSource
    - Hook

Hook.php

<?php
/**
 * User: nathanbrauer
 * Date: 3/18/15 4:52 PM
 */

class Hook extends SiteTreeExtension {

	function onAfterPublish(&$original) {
		var_dump("onAfterPublish"); die;
	}

	function onBeforeUnpublish() {
		var_dump("onBeforeUnpublish"); die;
	}

}