Automatically generated navigation homepage

[antonymilne]

The Homepage on https://vizro.mckinsey.com/ is currently written entirely manually but follows a very clear formula. Following #176 we now have a field Page.description and so all of the ingredients are in place with the exception of the page image. Somehow we should make it possible to automatically generate such a homepage. In theory this sounds pretty easy to do.

Major considerations

• What would be the right user API for it? A new HomePage model that subclasses Page? A Homepage model that includes a Page model? Just some Python helper functions? We'd like to follow our paradigm of extensibility and customisability and enable something that's possible from YAML too 🤔
• How does this all relate to Navigation and different ways of grouping pages in hierarchy?

Minor considerations

• How does page image fit into this? Should we change these to Google material icons? Do we want a Page.image field that's also used in meta tags (originally existed in Updating Meta Tags #176 but removed)? Or to automatically pick up an image with filename page.id? Could we generate preview images of the pages automatically as discussed in final point of this comment and subsequent responses?