Patterns and Practices: Master details, MVC, Separation of concerns, Command pattern
Copy your User Management Router project to a new git repository for the starting point
How to asynchronously load a JavaScript file after page load
var script = document.createElement("script");
script.src = "url to your script";
script.addEventListener("load", function(){ // script is loaded });
document.body.appendChild(script);
How to append a string of HTML to an element
var template = document.createElement("template");
template.innerHTML = html;
element.appendChild(template.content);