Add fastapi-cli while instaling fastapi

[icehongssii]

Summary of changes

The official doc said We can then serve the development version of the app using the fastapi cli tool - fastapi run. But the doc has never mentioned installing fastapi-cli. Thus, poetry add fastapi has to include fastapi-cli

poetry add fastapi fastapi-cli

Preview

Related Fly.io community and GitHub links

#1738

Notes