Adding some brief documentation

INSTALL.md

@@ -2,7 +2,14 @@
 
 Cachet is an open source replacement to [StatusPage.io](https://statuspage.io) written in PHP and the [Laravel](http://laravel.com) framework.
 
-You need at least PHP, [Composer](https://getcomposer.org/) and the `php-mcrypt` extension installed to run Cachet.
+You need at least PHP > 5.3, [Composer](https://getcomposer.org/) and the following PHP extensions installed to run Cachet:
+
+  - `php-mcrypt`
+  - `php-mbstring`
+  - `php-apc`
+  - `php-xml`
+  - `php-pdo`
+  - A database driver for your DB, such as `php-mysql`
 
 # Table of contents
 

docs/setup/centos6.md

@@ -0,0 +1,12 @@
+# Installing on CentOS 6
+
+The main issue with installing Cachet on CentOS 6 is the old PHP version. Laravel and Composer expect a version of PHP greater than 5.3, which is the default that ships with CentOS. You also need the same version of the required extensions.
+
+## Remi Repo
+
+To solve this problem, the 3rd party [http://rpms.famillecollet.com/](Remi Repo) can be used, which provides newer versions of PHP. 
+
+NOTE: This will upgrade existing versions of PHP on your system, so if you already have a PHP 5.3 requirement, you'll need to consider using [RedHat's Software Collections](https://access.redhat.com/documentation/en-US/Red_Hat_Developer_Toolset/1/html-single/Software_Collections_Guide/) and compiling the required extensions yourself.
+
+
+