refactor: move file inclusion to correct position

toml/traits.hpp

@@ -13,7 +13,6 @@
 #endif // has_include(<string_view>)
 #endif // cplusplus   >= C++17
 
-#include "comments.hpp"
 #include <vector>
 #include <unordered_map>
 

toml/value.hpp

@@ -11,6 +11,7 @@
 #include "region.hpp"
 #include "types.hpp"
 #include "source_location.hpp"
+#include "comments.hpp"
 #include <cassert>
 
 namespace toml