Create a run command

[daleal]

Given that most of the potential users of asymmetric are people who don't want to have to write a ton of code/learn multiple things to get their APIs running, maybe it would be a good idea to transform uvicorn into a dependency of asymmetric and provide a CLI command for running the API directly from asymmetric (something like asymmetric run module). Another option would be to conditionally import uvicorn with a try/except piece of code, provide the run CLI option and fail if uvicorn isn't installed. That could be a nice compromise (not requiring uvicorn if you're going to use another ASGI server to serve your API, but having the command in case someone wants to just plug and play, given that they also install uvicorn to be able to run it). The last option would be simply not to include a run command, and writing good documentation about ways to start the API that are very friendly to people new to the API development world.