Ability to pass a custom projectDir to the init script for monorepo templates

[Girish21]

The Remix CLI assumes that the app lives at the root of the project directory.

(Where the assumptions are made: remix-dev/cli/run.ts#L198, remix-dev/cli/run.ts#L355)

But in a monorepo, that is not necessarily the case. The app can live inside any sub directories based on the monorepo configuration. Example in this monorepo template for Remix + CF Workers, the app lives inside packages/remix-app.

It would be great if we could configure the project path :)