Added comment about remainder bits in QR symbol in all language versions.

cpp/QrCode.cpp

@@ -358,6 +358,8 @@ void qrcodegen::QrCode::drawCodewords(const std::vector<uint8_t> &data) {
 					modules.at(y).at(x) = ((data.at(i >> 3) >> (7 - (i & 7))) & 1) != 0;
 					i++;
 				}
+				// If there are any remainder bits (0 to 7), they are already
+				// set to 0/false/white when the grid of modules was initialized
 			}
 		}
 	}