Use case doc/article: sentry-native + crashpad + feedback (for game devs)

[kahest]

We're establishing Sentry as monitoring solution for game devs - we have good support for engines (Unreal, Unity, Godot) and consoles. Devs who don't use the engines can use sentry-native for their games - and many do. But we can do a better job communicating how to get started.

As a first step let's add an article to e.g. https://docs.sentry.io/platforms/native/advanced-usage/ on how to setup monitoring with sentry-native on custom game engine with crashpad, and how to utilize e.g. user feedback in that setup.