added codebook gist

Author: seankross

Codebook template.Rmd

@@ -13,3 +13,4 @@ permalink: /getclean/
 - [Second Codebook sample](https://gist.github.com/kirstenfrank/699abe3e16fd1dc36e5d)
 - [Query string (and other fields-within-fields) unrolling](http://rpubs.com/schnee/32988)
 - [Pre-processing Excel files before loading them into R](https://github.com/alkashef/cleaningexceldata)
+- [Codebook template that can be used in the Getting and Cleaning Data project](https://gist.github.com/JorisSchut/dbc1fc0402f28cad9b41)