At the bottom of your jquery.js, you have:
jQuery.noConflict();
jQuery.noConflict causes $ to be undefined, so you'll need to use the following in your snippet:
jQuery(document).ready(function () {
jQuery(".project-title").lettering('words');
});
As shown on the .ready() documentation, your function is passed jQuery as a variable, so you can name it whatever you want in local scope:
jQuery(document).ready(function ($) {
$(".project-title").lettering('words');
});
You can use the developer console in a modern browser to see the following error:
Uncaught TypeError: Property '$' of object [object Object] is not a function