Add some more documentation for beginners

[theheckwr]

Having just begun my journey with openziti and ZAC it would be helpful to have some more documentation.
Having had an issue with the tunneler config (openziti/ziti-tunnel-sdk-c#508), I suggest to add some configuration help to the ZAC.
Some examples from the top of my head:

• service configurations:
  • help the user to choose which config type to use (provide defaults?)
  • mark the optional/ required config options (if applicable use defaults)
• identities: info that an identity can be used only once (at least that's my experience)

I hope this isn't too vague. If I can help anything please let me know, I'll try to find some time. 😉

[dovholuknf]

Thanks for the issue! documenting the ZAC better is something we know we need to get through. Stay tuned, I'm sure we'll get around to it in the coming months

[qrkourier]

relatedly: #283