Start server by task

### What problem are you trying to solve?

I just realized that I can't deploy my server because it uses flags curious if this is a deliberate choice to omit creating a server using `deno task`. Kind of odd because `npm run start` is such a iconic way to start a server and there's no way to do the same in deno via deploy.

### Describe the solution you'd like

Default that `deno task start` would run the server as opposed to a single file entrypoint. Or allow the user to pick a task in the dropdown in deno deploy.

### Describe alternatives you've considered

I'm gonna have to re-write my server script to work without flags or work via env vars.

### Documentation, Adoption, Migration Strategy

_No response_