Collect data from usage

Have a script that provides data on usage of `gren` and project information.
It would be nice then to collect this data for internal usage.

_Q:_
- _need to prompt the user in order to ask?_
- _configuration per project?_

No file or test is named in the issue. Start by locating gren's usage entry point and any existing project configuration, then clarify whether prompting is required and what usage and project data should be collected. Done means the collection flow and configuration behavior are explicitly defined.

索引モデルが issue の本文から書いたものです。