adds more env variables

docker-compose.yml

 networks:
   default:
     external:
-      name: ${PREFIX}
+      name: ${DOCKER_PREFIX}
 
 services:
   adminer:
-    container_name: ${PREFIX}-adminer
+    container_name: ${DOCKER_PREFIX}-adminer
     image: adminer:4.7.2-standalone
     labels:
       - traefik.enable=true
-      - traefik.http.routers.${PREFIX}-adminer.entrypoints=https
-      - traefik.http.routers.${PREFIX}-adminer.rule=Host(`adminer.${PREFIX}.localhost`)
-      - traefik.http.routers.${PREFIX}-adminer.tls=true
-      - traefik.http.services.${PREFIX}-adminer.loadbalancer.server.port=8080
+      - traefik.http.routers.${DOCKER_PREFIX}-adminer.entrypoints=https
+      - traefik.http.routers.${DOCKER_PREFIX}-adminer.rule=Host(`adminer.${DOCKER_PREFIX}.localhost`)
+      - traefik.http.routers.${DOCKER_PREFIX}-adminer.tls=true
+      - traefik.http.services.${DOCKER_PREFIX}-adminer.loadbalancer.server.port=8080
   db:
     command: --default-authentication-plugin=mysql_native_password
-    container_name: ${PREFIX}-db
+    container_name: ${DOCKER_PREFIX}-db
     environment:
-      MYSQL_DATABASE: ${PREFIX}
+      MYSQL_DATABASE: ${DOCKER_PREFIX}
       MYSQL_PASSWORD: ${DB_USER_PASSWORD}
       MYSQL_ROOT_PASSWORD: ${DB_ROOT_PASSWORD}
       MYSQL_USER: ${DB_USER}
-    hostname: ${PREFIX}-db
+    hostname: ${DOCKER_PREFIX}-db
     image: mariadb:10.4.6-bionic
     volumes:
       - db:/var/lib/mysql
   web:
-    container_name: ${PREFIX}-web
+    container_name: ${DOCKER_PREFIX}-web
     image: wp-php7.3:dev
     labels:
       - traefik.enable=true
-      - traefik.http.routers.${PREFIX}-web.entrypoints=https
-      - traefik.http.routers.${PREFIX}-web.rule=Host(`www.${PREFIX}.localhost`)
-      - traefik.http.routers.${PREFIX}-web.tls=true
-      - traefik.http.services.${PREFIX}-web.loadbalancer.server.port=80
+      - traefik.http.routers.${DOCKER_PREFIX}-web.entrypoints=https
+      - traefik.http.routers.${DOCKER_PREFIX}-web.rule=Host(`www.${DOCKER_PREFIX}.localhost`)
+      - traefik.http.routers.${DOCKER_PREFIX}-web.tls=true
+      - traefik.http.services.${DOCKER_PREFIX}-web.loadbalancer.server.port=80
     volumes:
       - web:/var/www/html
       - wp-cli-cache:/var/www/.wp-cli
 
 volumes:
   db:
-    name: ${PREFIX}-db
+    name: ${DOCKER_PREFIX}-db
   web:
-    name: ${PREFIX}-web
+    name: ${DOCKER_PREFIX}-web
   wp-cli-cache:
     name: wp-cli-cache