title: Is there a way to run lint-staged only on new files (the ones that were untracked by git before)
body: <p>On my project written in Typescript I want to start enforcing type annotations for returned types and parameter types of all functions. For that I created a separate tslint config that extends my main config and adds this rule on top of that. I'm running tslint via husky and lint-staged with this extended config to check all staged files before committing changes. The problem is: if I do a change in one of the old files (some of them are pretty big) lint staged will check this file too and won't let me to commit unless I type-annotate all the functions in all files. But it's a lot of work and I want to enforce this only on new files. Is there a way to filter staged files to only ones that are added in this commit?</p>