Documentation on usage and use cases

[arkgil]

In a README, things that should be mentioned:

• Fennec is not a server, its servers
• how to start servers
• use cases (IoT, ..?)

[Dzol]

PR #8 introduced Fennec's rationale (really STUN rationale) and lists some helpful technical resources.

Let's keep the README small: it's not technical documentation on how to configure Fennec from a user perspective. Rather it's a GitHub landing page where we can introduce interested technical parties.

Use cases are more of a promotional thing and normally quite involved so a blog post would be ideal.

If agreed let's close this and open some other tickets.