adding exercise for docker compose

Teil1/db/Dockerfile

@@ -0,0 +1,12 @@
+# Use the official MySQL image from Docker Hub
+FROM mysql:latest
+
+# Set environment variables
+ENV MYSQL_ROOT_PASSWORD=root_password
+ENV MYSQL_DATABASE=employees
+
+# Copy the SQL initialization script into the container
+COPY init.sql /docker-entrypoint-initdb.d/
+
+# Expose port 3306 to allow external connections to the database
+EXPOSE 3306