The Vue JavaScript framework is "reactive," which means it can automatically refresh your data. Learn the ways you can take advantage of this in your apps.
To display items in a hierarchical, tree-like structure with expandable parent and child nodes, you need a treeview. See how you can easily create and style a custom treeview in Kendo UI.
Why TypeScript might be a good fit for your next project: tips for choosing - or not choosing - TypeScript. (Plus a video recording of TJ VanToll's DevReach talk on the subject)