Feature Request: Command to add a dependency/package

Most build tools have a command to add a dependency to your project (e. g. `npm install`). If I'm not mistaken there currently is no such command in cabal and `install` and `get` might be misleading.

Is it possible to add such command? Or is there a reason against or this issue being a duplicate?

Thanks :)

Start by reviewing cabal-install's existing `install` and `get` commands and how dependency changes are represented in a project. Define the proposed command's behavior and resolve whether the request duplicates existing functionality; done requires an agreed command and scope.

Written by the indexing model from the issue text.