adding comments

src/minefield.cpp

@@ -119,6 +119,7 @@ void MineField::setOpenCell(int x, int y) {
   m_cells.at(x + y * m_rows)->isCleared = true;
   openCellSignal.emit(x, y);
   if((++m_openCells == (m_cols * m_rows - m_totalMines)) && (m_exploded == false)) {
+    m_gameWon = true;
     gameWonSignal.emit();
   }
 }