Introduce "dev environment" and dotenv

There are now two dockerfiles. One for production, one for development.
All configuration is now also handled through dotenv files,
which these dotenv files, as well as the included VSCode launch tasks
use.

docker-compose.prod.yml

@@ -1,10 +1,15 @@
 version: "3.9"
+
+secrets:
+  secrets:
+    file: ./secrets.yml
+
 services:
   karaoqueue:
     image: "phillipkhne/karaoqueue:latest"
     restart: always
     ports:
-      - "127.0.0.1:8081:80"
+      - "127.0.0.1:8081:80" # Please put a reverse proxy in front of this
     environment:
       DEPLOYMENT_PLATFORM: Docker
       DBSTRING: mysql://user:pass@host:3306/database
@@ -16,8 +21,8 @@ services:
     image: mariadb
     restart: always
     environment:
-      MARIADB_ROOT_PASSWORD: dpMAZj*Mc4%FZM!V
+      MARIADB_ROOT_PASSWORD: changeme!
       MARIADB_ROOT_HOST: localhost
       MARIADB_DATABASE: karaoqueue
       MARIADB_USER: karaoqueue
-      MARIADB_PASSWORD: a5G@P*^tCW$$w@wE
+      MARIADB_PASSWORD: change