#1 Ignore nunjucks files on compile

Nunjucks files are not being ignore on compile, so you end up with index.html and index.nunjucks in your public folder.

This PR adds .nunjucks and .njk to ignored files on compile.

Thank you dearly for your contribution, @charlesrt!

Published Wick 0.23.1 to npm. Thank you, @charlesrt!

You're welcome. Keep up the great work. Harp and Wick are refreshingly simple to use :)