Move mobile detect into strings category.

README.md

 * [Text](https://github.com/kzykhys/Text) - A text manipulation library.
 * [SQL Formatter](https://github.com/jdorn/sql-formatter/) - A library for formatting SQL statements.
 * [UA Parser](https://github.com/tobie/ua-parser/tree/master/php) - A library for parsing user agent strings.
-* [Device Detector](https://github.com/piwik/device-detector) - Universal Device Detection library will parse any User Agent (browser, os, type, brand and model)
+* [Device Detector](https://github.com/piwik/device-detector) - Another library for parsing user agent strings.
+* [Mobile-Detect](https://github.com/serbanghita/Mobile-Detect) - A lightweight PHP class for detecting mobile devices (including tablets).
 
 ## Numbers
 *Libraries for working with numbers.*
 * [PHP-GPIO](https://github.com/ronanguilloux/php-gpio) - A library for playing with the Raspberry PI's GPIO pins.
 * [print_o](https://github.com/koriym/print_o) - An object graph visualizer.
 * [Alias](https://github.com/fuelphp/alias) - A class aliasing library.
-* [Mobile-Detect](https://github.com/serbanghita/Mobile-Detect) - A lightweight PHP class for detecting mobile devices (including tablets).
 
 # Software
 *Software for creating a development environment.*