Add example how to use the embedded container

README.md

@@ -1,3 +1,18 @@
+## Using as an embedded Docker Compose service
+
+```
+services:
+  oauth2:
+    build: https://gitea.dsv.su.se/DMC/oauth2-authorization-server.git
+    restart: unless-stopped
+    ports:
+      - "<host_port>:8080"
+    environment:
+      CLIENT_ID=awesome-app
+      CLIENT_SECRET=p4ssw0rd
+      CLIENT_REDIRECT_URI=http://localhost/oauth2/callback
+```
+
 ## Development
 ### Prerequisites
 - JDK 17 (or later)