Edit requests of Swift Stringの切り出し、文字列操作について(Swift4のsubstring周りの挙動変更対応, Swift5対応バージョン, Swift5.3対応バージョン）

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We released Markdown parser changes on February 24, 2022. There may be some unexpected appearance changes in this update, because this article was posted before the changes.
Please don't forget to check the preview before updating your article.
For more information on the changes, please read this article.