docs: provide helpful example on how to enable password auth when using docker compose

[wmundev]

• provide helpful example on how to enable password auth when using docker compose so that whoever uses docker compose can easily add password auth if they wanted to

[badrishc]

Instead of editing docker-compose.yml, we should add this documentation here:

https://microsoft.github.io/garnet/docs/welcome/releases

Can do this by a PR to this file: https://github.com/microsoft/garnet/blob/main/website/docs/welcome/releases.md

[wmundev]

thanks badrishc, i've updated the PR, something like this? https://github.com/microsoft/garnet/pull/209/files#diff-0348affd91795660ce75ed4eead47960881f2511e6b5f63b224680c4f044d161R41