List apps in categories directly on homepage

Something we discussed on an AppCenter design call.

## Problem

We hear that AppCenter looks/feels empty. Most app stores have a ton of apps right on the home page. Anecdotally, I never really browse via the categories but I just use search.

## Proposal

We could promote more exploration and discovery (and make the homepage much more lively!) by placing categorized apps directly on the homepage under associated categories. Then each category could have a "view all" button to take you to the existing category list view.

## Prior Art

Google Play Store has a huge homepage with a mix of traditional categories, "premium" apps, "low on space?" apps, ads, etc. to promote scrolling and discovering from the start.