we can now print a move (stockfish stile)

cpp/src/move.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "castle_side.hpp"
+#include "coords.hpp"
 #include "pieces/piece.hpp"
 
 #include <cstdint>
@@ -14,3 +15,9 @@ struct Move {
     bool en_passant = false;
     int8_t promoting_to = Piece::None;
 };
+
+inline std::ostream& operator<<(std::ostream& os, const Move& m) {
+    os << Coords::from_index(m.source_square)
+       << Coords::from_index(m.target_square);
+    return os;
+}