Clean up README and INSTALL documents

[mbjones]

README file cleanup

The current README.md is a template and needs to be updated with vegbank-specific details. These include:

• Link to vegbank2 Discussions rather than DataONE Discussions
• Fix names/URLS for the 3 repositories
• Change "Usage Example" to "API Usage" and write something like TBD under it

Later we'll clean up more things including the author list and citation details

INSTALL file cleanup

• Bring instructions from helm/README.md into INSTALL.md
• Reorganize into 3 clean sections
  1. Data migration -- How to take a Postgres dump file from the original VB DB, and (locally) create a version of this that is compatible with and loadable into the new PG version
  2. Chart installation -- How to deploy Postgres to K8s using Helm, as part of our new VegBank storage service
  3. Database restore -- How to restore a current DB dump file (i.e., what you produce in step 1, or by creating a dump file from the new system) to the Postres instance running on K8s (i.e., what you have after running step 2)
• Clean up the Docker instructions in the current INSTALL file ... at least rid of the console output, and make it clear that this is an alternative to the local installation of PG/Flyway
• Add instruction to tar/compress the dump file before copying over to the cluster
• Do some minor formatting cleanup
  • Add code tags
  • Use section delimiters where appropriate (##)
  • Remove trailing whitespace