macOS Metal + AppKit app (#2205)

Co-authored-by: mwilsnd <mwilsnd@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

.clang-format

@@ -9,10 +9,14 @@ BinPackParameters: false
 ColumnLimit: 120
 IncludeBlocks: Preserve
 IndentWidth: 4
-Language: Cpp
 PackConstructorInitializers: Never
 PenaltyBreakAssignment: 80
 SortIncludes: false
 SpacesBeforeTrailingComments: 1
 Standard: c++17
+---
+Language: Cpp
+---
+Language: ObjC
+BasedOnStyle: Google
 ...