[clang] [clang-format] Add FilesBeforeFolders option to SortIncludes (PR #208954)

[Savvas Shiakas via cfe-commits]

Shiakaron wrote:

Hi there, @HazardyKnusperkeks @mydeveloperday, I found your names in the 'clang-format' section of `clang\Maintainers.md`. I am in the process of ticking of the boxes for the project but If I missed anything please do let me know. Thanks

https://github.com/llvm/llvm-project/pull/208954