[Feature Request] Choose a repo when opening plannotator-review in a workspace with multiple repos

[ben-reitz]

I often have my pi agent open in a directory containing multiple semi-related repositories it can access and reference for a specific task. I'd like to use /plannotator-review to check the latest commit for the repo i've been working in only, but by default that opens up changes for all repos in the current workspace, and i can't see an option to just select one of them. It'd be cool if I could pass in an argument for a path to /plannotator-review

# e.g. something like this
/plannotator-review ./repoOrFolderIWantToReview

# or this if you want current workspace dir to be default root
/plannotator-review repoOrFolderIWantToReview