Document APIcast parameters about apicast

[mikz]

We try to document them in https://github.com/3scale/apicast/blob/v2/.env

[andrewdavidmackenzie]

Agree good to document somewhat in one 'doc' that is not code, but having in too many places causes an update overhead.

Thinking about your (valid) example of someone installing from OpenShift template and not seeing the code.... made me wonder what documents or mechanisms for showing information are available.... I think Joaquim mentioned to me the ability to embedd some "notices" in the template itself and they are shown to the user .... for that use case that might be a better place?

[mikz]

Someone installing from OpenShift template will see all of them as template parameters in the UI. Each param has description.

[mayorova]

Closed by #192