Improve initial setup

[kevoconnell]

Today you need a ABI_DATABASE_URL with the correct schema to run this indexer

Please do the following:

1.) allow the user to opt out of any embedding generation and inserting into ABI_DATABASE_URL, as well as REDIS_URL usage.

2.) create a script and/or migration file to set up the database as needed. update the .env.example to provide a redis url and postgres db to point to. Additionally, make sure that the user has the needed environment variables when starting, if they dont throw an error