Making changes to javascript files - SB Premium Elbrus

I was able to find the .tpl files, got node.js, gulp.js installed made successful changes to some of the look, but I wanted to include some items - in this case - shipping cost - on the invoice overview page.

I figured I could change the associated javascript file to pull in that information. Here is where I made that change in this file here - Invoice.OpenList.View.js

And it's not showing on the UI.

childViews: {
                'ListHeader': function ()
                {
                    return this.listHeader;
                }
            ,    'Invoice.Results': function ()
                {
                    var records_collection = new Backbone.Collection(this.collection.map(function (invoice)
                    {
                        var model = new Backbone.Model({