[FEAT] Add environment variable for LOG_LEVEL

[instantdreams]

Please consider adding an environment variable for adjusting the logging level to the console output which is typically viewed in the docker logs.

For example if the variable was LOG_LEVEL and it supported the standard enums of CRIT, ERROR, WARN, INFO, DEBUG, it would adjust the output send to the log.

I have been able to adjust the telamate grafana log level using the following environment variables:

GF_PATHS_LOGS=/var/log/grafana
GF_LOG_MODE=console file
GF_LOG_LEVEL=warn
GF_LOG_CONSOLE_FORMAT=console
GF_LOG_FILE_FORMAT=json
GF_LOG_FILE_LOG_ROTATE=true
GF_LOG_FILE_DAILY_ROTATE=true
GF_LOG_FILE_MAX_DAYS=14

I've also added the following to the postgres compose file structure:

    command: postgres -c log_min_messages=WARNING

Enabling logging level support for teslamate would be the cherry on the top.

Thank you for considering this!