Add instructions on how to deploy the api (copied from onflow/wallet-api)

[latenssi]

From @hichana

I realize the wallet-api is not production-ready yet, but it would be great to have some instructions on how to deploy the api on a cloud provider like GCP. The wallet-api seems pretty powerful so for some it might be wise to start preparing for using it in a real-world app.
Also, how where in the repo is the actual code that starts the server to run the api? I'm not familiar with docker so maybe this is what I'm missing here. I guess the docker image has all of this and is building and running it? Some help/guidance in the readme for this would be appreciated too. Thanks!

some instructions to deploy on Kubernetes, or even something easier (if possible) like Google Cloud Run would be nice

From @psiemens:

Thanks for the feedback, @hichana! I agree that there should be instructions for how to deploy to a cloud environment.

[latenssi]

Closing as duplicate of #150