core: Add clang-tidy (#8664)

This adds a .clang-tidy file for us.

It's not a strict requirement to be compliant, but I tuned it to be alright.

src/helpers/math/Math.hpp

@@ -6,6 +6,7 @@
 #include <hyprutils/math/Region.hpp>
 #include <hyprutils/math/Mat3x3.hpp>
 
+// NOLINTNEXTLINE
 using namespace Hyprutils::Math;
 
 eTransform          wlTransformToHyprutils(wl_output_transform t);