Handbook Page: How to use the Project Browser

Problem/Motivation

All core modules need a handbook page, whether or not they provide and API, and contrib modules should have one.

Proposed resolution

We need to write our own handbook page which explains how to use the project browser and what each filter and function does. Here, we can explain some of the "insider" things, like what we mean when we say "maintained" and how the browser should only show you modules that are compatible with your Drupal site.

A good "top-to-bottom" walkthrough should be created, ideally including screenshots.''

We might consider either adding to this, or having a separate page, for how to configure the project browser (ex.g. adding in the core source plugin, etc.)