Add cmake support

cmake/compile_flags.cmake

@@ -0,0 +1,13 @@
+function(adaptive_brightness_add_compile_flags target)
+    if(MSVC)
+        target_compile_options(${target} PUBLIC /MP)
+    endif()
+endfunction()
+
+function(adaptive_brightness_enable_warnings target)
+    if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang|AppleClang")
+        target_compile_options(${target} PRIVATE -Wall -Wextra -pedantic)
+    elseif(MSVC)
+        target_compile_options(${target} PRIVATE /W3)
+    endif()
+endfunction()