small changes in volume gestion for db

srcs/docker-compose.yml

@@ -46,6 +46,7 @@ services:
         - DB_NAME=${DB_NAME}
         - DB_USER=${DB_USER}
         - DB_PSWD=${DB_PSWD}
+        - DB_VOLUME_DIR=${DB_VOLUME_DIR}
     healthcheck:
       test: mariadb -h ${DB_HOST} -u ${DB_USER} -p"${DB_PSWD}" -e exit 2> /dev/null
       interval: 1s
@@ -76,6 +77,7 @@ services:
         condition: service_healthy
 
 # specify path to named volumes : https://docs.docker.com/compose/compose-file/compose-file-v3/#volume-configuration-reference
+# local driver options : https://stackoverflow.com/questions/62232676/docker-local-volume-driver-options
 volumes:
   db_volume:
     driver: local