Updated function reference in document's docstring.

Hello!

Thanks for sharing Laser!  It's a really neat way of thinking about templating (I'm relatively new to templating and have been exploring the different approaches).

I'm really new to open source pull requests, (this is my second), feel free to give me feedback on anything I could improve about this pull request :)

* Updated function name (from parse-html to parse) reference in fn document's docstring.

Wolfe