Update README.md - small typo

As part of my day job I review policies and standards, and this one came up recently. Small, but very common typo.
Merge pull request #882 from curtisk/patch-1

Update README.md - small typo
Added random number generator.

Stolen from https://gist.github.com/chriseppstein/1561650
Added random function
Added random numner genreator