ESC: How do I migrate from config and secrets in stack config files to ESC envs?

[jkodroff]

ESC was in part designed to solve the downsides of using stack config files at scale, but we do not have any migration guidance in the docs that I can find.

We talk about how ESC integrates with IaC: https://www.pulumi.com/docs/esc/integrations/infrastructure/pulumi-iac/

We have a command that talks about how to move an individual stack file to an ESC environment (although it is not mentioned in the previous link): https://www.pulumi.com/docs/iac/cli/commands/pulumi_config_env_init/

But we don't have any page that gives a walkthrough of how we recommend people migrate. It doesn't have to be applicable to a massive number of stacks - if someone is using Pulumi at massive scale they likely have paid support - but it should at least cover how to get people onboarded onto ESC so they can quickly see how useful it is.