[stzn/the-swift-programming-language-jp] Pull request closed: #678 [Style.md、宣言、属性]Swift6のエラーがコンパイルエラーであることを明記

[stzn/the-swift-programming-language-jp] Issue closed: #668 Deprecation errorsの記述更新

[stzn/the-swift-programming-language-jp] Pull request closed: #677 [宣言]in-outのexampleに引数ラベルを追加

[stzn/the-swift-programming-language-jp] Issue closed: #669 in-outパラメータの例に引数ラベルを付ける