Fix missing library for C++17 filesystem

CMakeLists.txt

@@ -71,6 +71,12 @@ target_link_libraries(AdaptiveBrightness
                       Qt5::SerialPort
 )
 
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang|AppleClang")
+    target_link_libraries(AdaptiveBrightness
+                          stdc++fs
+    )
+endif()
+
 if(MSVC)
     target_link_libraries(AdaptiveBrightness
                           Dxva2.lib