Add Custom Jade tags

index.jade

doctype html
html
  head
    title Hi
  body
    div
      span= formatDate('Dec 25, 1995')

index.js

var j = require('jade'),
    m = require('moment');

var locals = {
    formatDate: function( str ) {
        return m(str).format();
    }
};


console.log(j.compileFile('index.jade')(locals));