added Laravel 3 Installation

docs/installation-l3.rst

@@ -0,0 +1,22 @@
+Laravel 3 Installation
+======================
+
+1. Install using Artisan, or download the zipball from GitHub
+::
+
+	php artisan bundle:install piwik
+or
+::
+
+	git clone https://github.com/RobBrazier/Laravel-Piwik.git piwik
+
+2. Add laravel-piwik to your bundles.php
+::
+
+	'piwik' => array('auto'=>true, 'handles'=>'piwik_install'),
+
+and go to http://yourdomain.com/piwik_install
+
+This is a user-friendly way to fill out the config file, just because I thought that'd be nice :)
+
+(Incase you're wondering, `here <http://cl.ly/image/Kddc>`_'s a screenshot).