Unclear from docs where API_HOST and API_AUTH are provided

[brian-labelle]

It's not clear where API_HOST and API_AUTH come from, or how they are meant to be populated in params.

e.g., the following code

new Openwhisk(params.API_HOST, params.API_AUTH)

Let's use an external product update as an example -- how are these values populated for params, in order to ensure that the OpenWhisk action is properly invoked?