Ability to deploy workspace packages easily?

### What problem are you trying to solve?

In order to run a package in a deno workspace, you're to `cd` into the directory and run the command. This isn't something I think that you can do in deno deploy - you can either deploy a subdirectory or set the appropriate entrypoint.

1. Deploying a subdirectory doesn't work, because the package loses access to the other packages in the repository (as they are not copied).
2. Setting the entrypoint doesn't work, because this diverges from the development workflow. Now all your paths are broken, potentially.

### Describe the solution you'd like

Ideally? Specify the package to deploy in the workspace in the project settings.

At the least? Specify the working directory that the Deno Deploy process runs from.

### Describe alternatives you've considered

To get it working for my use case, I added a "PROJECT_ROOT" environment variable that allows me to basically specify the diff between where the process is running in the project and where the project itself lives. This adds complexity and couples one's architecture to the deployment solution - unideal.

### Documentation, Adoption, Migration Strategy

Here's the project root: https://github.com/daniellacosse-code/onlyweb
And the subfolder I'm deploying: https://github.com/daniellacosse-code/onlyweb/tree/main/.examples/onlyweb.dev

How you could expose it in the Deno Deploy UI? I might put a "Select Package" option under Project Configuration.