Update documentation on how to configure hooks

In reference to issue #1

README.md

@@ -8,30 +8,26 @@ at `Special:Log`.
 
 * Download and place the file(s) in a directory called ActivityLog in your extensions/ folder
 * Add the following line to your LocalSettings.php
-```
+```php
 wfLoadExtension('ActivityLog');
 ```
 
 ## Usage
 
-Enable through adding to the `$wgActivityLogHooksToWatch` global variable,
-then viewing through the Special:Log page.
-
-The page title, hook name, and user are logged to the main Log page.
-
-## Parameters
+Configure new hooks by adding them to the `$wgActivityLogHooksToWatch` array in
+LocalSettings.php.
 
-* `$wgActivityLogHooksToWatch` - The hooks to watch
-
-Update by setting the key in the associative array to true, for any hook.
-For example, you can log user logins via:
-
-```php
-$wgActivityLogHooksToWatch["UserLoginComplete"]
+``` php
+$wgActivityLogHooksToWatch['ArticleViewHeader'] = function ($article) {
+    return 'Visited article "' . $article->getTitle() . '"';
+};
 ```
 
-All the normal arguments that would be passed to those hook executions are
-discarded.
+`$wgActivityLogHooksToWatch` takes booleans, strings, and anonymous functions. A
+`true` value will log the hook name, A string will log the string itself, and a
+callback will be invoked with all the arguments that are passed by the hook.
+
+[https://www.mediawiki.org/wiki/Manual:Hooks](https://www.mediawiki.org/wiki/Manual:Hooks)
 
 ## Internationalization