Fix code tags in the README for docker-compose
Fix code tags in the README for docker-compose

nickjj/build-a-saas-app-with-flask,z123/build-a-saas-app-with-flask,z123/build-a-saas-app-with-flask,nickjj/build-a-saas-app-with-flask,z123/build-a-saas-app-with-flask,nickjj/build-a-saas-app-with-flask,nickjj/build-a-saas-app-with-flask