Add documentation for installation, maintenance, etc

[gothub]

This documentation will include these topics:

• the initial k8s installation
• updating the k8s software version
• Let's Encrypt licensing
• use of DNS cname api.dataone.org, api.test.dataone.org
  • add docs from https://hpad.dataone.org/wz4Y9W8gQcG4RLIl_facYg to this repo
• setup of persistent volumes and how to access with volume claims

Much of this documentation will be redirects to existing k8s from https://kubernetes.io/docs and other sources, with added comments for setup or additional information.

[amoeba]

What did we decide about being able to or wanting to front services not running on the clusters behind the ingress controllers? Would that be useful to document?

[gothub]

@bryce this is documented here. This documentation will be added to either this repo or DataONEorg/api-entrypoint.

[gothub]

@bryce btw - have a look under the 'NGINX Ingress Controller' and 'NGINX Inc. Ingress Controller' headings.

[amoeba]

Looks good, the example config and curl command are especially helpful.