Setting timezone via TZ env var

[BendingBender]

Is your feature request related to a problem? Please describe.
I'd like to be able to specify a timezone for the docker containers.

Describe the solution you'd like
I'd implement an extension for all docker images that installs the tzdata package and set the env var TZ via .env file to explicitly specify a timezone.

Describe alternatives you've considered
I know that time zones can be specified in the elastic instance, however there is a merit to be able to have logs in the correct timezone.

Additional context
Please tell me if you would accept this feature if I make a PR.