Add an FAQ and/or high-level overview of how to integrate TUF

We are often asked the same questions regarding delegations, how to organize TUF metadata, key management, etc. There should be an FAQ page for these sorts of questions.

The Survivable Key Compromise paper provides an overview of TUF's design, and the specification and other documents available here capture most of what it contains. However, the integration side of things is not adequately explained outside of the Diplomat and Mercury papers. The PEP 458 document is also a good resource for how to integrate TUF with an existing software updater and community repository.

We should provide a condensed, high-level document that contains the information in the papers and documents that have been written since the Survivable Key Compromise paper.

Prüfe die Papers Survivable Key Compromise, Diplomat und Mercury sowie das Dokument PEP 458 und vorhandene TUF-Spezifikationsmaterialien. Fasse ihre Integrationshinweise in einer kompakten FAQ oder einem Überblick auf hoher Ebene zusammen, der Delegationen, die Organisation von Metadaten und die Schlüsselverwaltung abdeckt; abgeschlossen ist die Aufgabe, wenn die wiederkehrenden Integrationsfragen in einem zugänglichen Dokument erklärt werden.