Edit requests of 【備忘録】idやclassの先頭文字に数字は使えないけど、使いたいときにやること（使いたい時は、数字をエスケープする）

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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.