Add a link to all available Docker variables

[guillempuche]

The Go library contains all the available keys https://github.com/openfga/openfga/blob/main/cmd/run/flags.go that we can put in our Docker (Docker Compose in my case), like OPENFGA_ACCESS_CONTROL_STORE_ID or OPENFGA_HTTP_CORS_ALLOWED_ORIGINS. And also for the Migrate service https://github.com/openfga/openfga/blob/main/cmd/migrate/flags.go.

It'd be good to point them out in the docs at https://openfga.dev/docs/getting-started/setup-openfga/docker.

[rhamzeh]

@guillempuche does the suggestion in #267, implemented in #938 (Demo: https://openfga.dev/pr-preview/pr-938/docs/getting-started/setup-openfga/configuration) work for you?

If yes, we can reword this ticket to talk about migrate specifically

[guillempuche]

Yes, this is great!