[FR] Add better documentation and examples

[soonerfan]

Is your feature request related to a problem? Please describe.
I am using apigeecli in a Github action to import /deploy proxies to Apigee on Google Cloud using OpenAPI specs. The tool was pretty straight forward for doing that. Now I need to register the API to Apigee API Hub and I am struggling a bit to figure out how to provide the properties to send to API Hub

Describe the solution you'd like
Please provide samples of how to use apigeecli to add an API to Apigee API Hub

Describe alternatives you've considered
I have looked at other tools, but since I am already using apigeecli in Github actions, I have no desire to use a different tool

Additional context
Sample would be very helpful in this case since the command line help doesn't provide enough information in this case