uci: 针对 Issue #80 添加代码注释

void position(Position *pos, istringstream &is)
添加一行 TODO 注释

// TODO: Stockfish does not have this
Threads.main()->us = pos->sideToMove;

src/uci.cpp

@@ -89,6 +89,7 @@ void position(Position *pos, istringstream &is)
 #endif // THREEFOLD_REPETITION
     }
 
+    // TODO: Stockfish does not have this
     Threads.main()->us = pos->sideToMove;
 }