EdgeDB fly.io deployment guide review

https://www.edgedb.com/docs/guides/deployment/fly_io

• Could update all flyctl commands to just fly
• After flyctl pg create, need to scale by pulling the machine ID out of the output of pg create (e.g., Machine xxxxxxxxxxxxxx is created) and feeding that into flyctl machine update xxxxxxxxxxxxxx --memory 512 --app $PG_APP