Add startup script and update Dockerfile and docker-compose.yml

Dockerfile

@@ -19,8 +19,13 @@ RUN npm run build
 # Expose the port that the app is listening on
 EXPOSE 3000
 
+
+RUN chmod +x ./startup.sh
+
 # The USER instruction sets the user name to use as the default user for the remainder of the current stage
 USER node:node
 
-# This is the command that will be run inside the image when you tell Docker to start the container
-CMD ["node", "build/index.js"]
+# get permission to run startup script
+
+# Run startup.sh instead of the default command
+CMD ["./startup.sh"]