qqnormsim() not sourced?

`qqnormsim()` is great! But looking at the [html version of Exercise 3](http://htmlpreview.github.io/?https://github.com/andrewpbray/oiLabs-base-R/blob/master/normal_distribution/normal_distribution.html) doesn't make it clear how to define the function. Perhaps either include a `source()` command or put it in a CRAN package and use `::`?