Pull Request Overview

This PR translates the HTML element documentation from English to Japanese for the /docs/reference/html/elem/ page. The translation covers the main documentation comments for the HTML element functionality in Typst, explaining how users can create custom HTML elements with more control over the output.

• Updates translation status from "untranslated" to "translated" for the HTML elem reference page
• Translates all documentation comments in the HTML element module from English to Japanese
• Provides Japanese explanations for HTML element creation, validation rules, and usage examples

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

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翻訳ありがとうございます。対応が遅くなりすみません。
概ね問題ないと思います。細かいコメントだけ入れました。