[BUG] invalid section names in ToC

[lstuma]

General Information
Version:
Installation Method: nix-shell -p wiki-tui
Operating System: nixos

Used configuration (if available):

Describe the bug
A clear and concise description of what the bug is. (see e.g. https://zh.wikipedia.org/wiki/Git)

Section names containing html are displayed wrongly in table of contents (see https://github.com/Builditluc/wiki-tui/blame/60c52592fe5fafc62a9769099962317c4d2e7d6c/wiki-api/src/page.rs#L523)

To Reproduce
Steps to reproduce the behavior:

1. Go to wikipedia article of Git
2. Switch language to chinese
3. See wrong section name in section 4

Expected behavior
A clear and concise description of what you expected to happen.

Section names should be displayed correclty as on the wikipedia page.

Screenshots
If applicable, add screenshots to help explain your problem.

wiki-tui displays section 4 (库目录) wrongly in table of contents

Crash report (if available)
If available, upload the crash report for further information

Additional context
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Checklist

• checked other issues for the same bug
• read CONTRIBUTING.md