Docker compose instruction for adding LocalSettings.php could be clarified #2669

The comments within docker-compose.yml contain the following:

# After initial setup, download LocalSettings.php to the same directory as
# this yaml and uncomment the following line and use compose to restart
# the mediawiki service

Simply restarting the service is insufficient. To add the new volume you need to use the following command:

docker compose up --build

It is not necessary to first do docker compose down.