There are still a few topics that should be coverred. Here are some of them, together with helpful resources.
How to write a SPA?
Article: Passing the State down/sharing State across pages
Article: Page Navigation
Article: URL handling
Designing Elm package APIs
Article: Publishing an Elm Package
Article: Extendable Records and Thread
Making impossible states Impossible
Article: Dropdown menus
Article: Working with Forms and Blog
Article: Web Workers
Article: Drag and Drop
Thread: Keyboard input