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/managers/LayoutManager.hpp

@@ -16,7 +16,7 @@ class CLayoutManager {
     std::vector<std::string> getAllLayoutNames();
 
   private:
-    enum HYPRLAYOUTS {
+    enum eHyprLayouts : uint8_t {
         LAYOUT_DWINDLE = 0,
         LAYOUT_MASTER
     };