Move copyright to the top of files.

src/ftxui/dom/reflect.cpp

@@ -1,3 +1,6 @@
+// Copyright 2020 Arthur Sonzogni. All rights reserved.
+// Use of this source code is governed by the MIT license that can be found in
+// the LICENSE file.
 #include <memory>   // for make_shared, __shared_ptr_access
 #include <utility>  // for move
 #include <vector>   // for __alloc_traits<>::value_type
@@ -43,7 +46,3 @@ Decorator reflect(Box& box) {
 }
 
 }  // namespace ftxui
-
-// Copyright 2020 Arthur Sonzogni. All rights reserved.
-// Use of this source code is governed by the MIT license that can be found in
-// the LICENSE file.