added jquery-treegrid

* The origin of your library files (e.g., where you downloaded it)
https://github.com/maxazan/jquery-treegrid

* How you found the version of the script (e.g., `Source: http://github.com/example/releases/1.2.3.zip`)
https://github.com/maxazan/jquery-treegrid/archive/0.2.0.zip