Add GitHub Container Registry

.gitignore

@@ -2,3 +2,5 @@
 .env
 docker-compose.override.yml
 .idea
+
+.secret

README.md

@@ -9,6 +9,8 @@
 
 The fastest way to get started is using [Docker Compose](https://docs.docker.com/compose/):
 
+* **IMPORTANT**: Ensure that you have logged in to the GitHub Container Registry.
+  * Follow the steps described here: https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-container-registry#authenticating-with-a-personal-access-token-classic
 * Create a `.env` file by coping it from `_.env`
 * Add your publicly available FQDN or IP address to the `PUBLIC_HOSTNAME` variable in the `.env` file and save it\
   (see also [I don't know my public IP](#i-don't-know-my-public-ip))

docker-compose.yml

@@ -47,14 +47,8 @@ services:
       - '8092:8080'
     networks:
       - opentosca
-  engine-ia-jdk8:
-    image: opentosca/engine-ia:latest-jdk8
-    ports:
-      - '8090:8080'
-    networks:
-      - opentosca
   engine-ia-jdk17:
-    image: opentosca/engine-ia:latest-jdk17
+    image: ghcr.io/opentosca/engine-ia:master
     ports:
       - '8093:8080'
     networks: