create docker-compose.yml

create api-gateway/Dockerfile

create notification-service-hard/Dockerfile

create api-gateway/index.js

create notification-service-hard/index.js

create order-service-hard/index.js

create user-service-hard/index.js

create example-hard.md

delete example.md

create example-easy.md

create example.md

update user-service/users.json

create order-service/orders.json

create order-service/index.js

create user-service/users.json

create user-service/index.js

update setting-VM-to-PC.md

create setting-VM-to-PC.md