Inspired by [1].
Passing --changed-only will format uncommitted, edited files.
Passing --changed-only <path> will format uncommitted, edited files
lying on the <path>, i.e., it will usually narrow down the number
of files to be edited.
The long list of intern/* has been shortened since it is out of sync
with the current directory structure and adds a maintenance cost.
[1] https://github.com/llvm/llvm-project/blob/master/clang/tools/clang-format/git-clang-format