Should recognize .env file in baseroot

[zishanj]

It's better if the docker can recognize .env file in its root directory. Following is the working code in bin/moodle-docker-compose

# Load .env if it exists
if [ -f "$basedir/.env" ]; then
  export $(grep -v '^#' "$basedir/.env" | xargs)
fi

It's very handy.

[paulholden]

There's ongoing work in #249 to implement this