Feature request: Repository.getFileCreatedDate

[baodrate]

I have a use case that needs to know the date a file was initially added to the repository. i.e. getFileCreatedDate. It should have the semantics of git log --follow (see libgit2: Rename Detection and git_diff_find_options). Would you be open to a PR that implements this?

Alternatively, could enough of the libgit2 API be exposed that this could be implemented in the js side? although I'm not sure if this could be both performant and not break simple-git's design constraints