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• I have read the Contributing Guidelines on issues.

Prerequisites

• I'm using the latest version of Docusaurus.
• I have tried the npm run clear or yarn clear command.
• I have tried rm -rf node_modules yarn.lock package-lock.json and re-installing packages.
• I have tried creating a repro with https://new.docusaurus.io.
• I have read the console error message carefully (if applicable).

Description

The generated tables of contents (ToC) for a markdown page includes headings inside collapsed <details>. Clicking the ToC link does nothing.

This was mentioned back in #5790. I haven't found anything in the [HTML5 spec](https://html.spec.whatwg.org/#the-details-element section on <details>) about disallowing heading content inside it. Some online sites such as https://a11ysupport.io/tech/html/summary_element reference them being allowed. https://stackoverflow.com/questions/49594772/should-i-specify-h2-h6-sub-headings-for-a-details-tag-to-make-the-details-a-dist#:~:text=Headings%20within%20details,)%2C%20provide%20heading%20elements%20within even references it being preferred (though I again can't find a source).

See the typescript-eslint site and PR referenced in this issue for an example of where I'd want this. Specifically, I wanted to include headings inside a details view because there's a lot of content that could benefit from having sections. The details content isn't something most page readers need, though, so I didn't want to have the reading journey on the page include it so early.

Reproducible demo

https://j2rm6f.sse.codesandbox.io/markdown-page

Steps to reproduce

1. Add a <details> element to a markdown page
2. Include a ## ... heading inside that details element
3. View the markdown page

Expected behavior

I would think one of the two would happen:

• Clicking the ToC heading would expand the <details> element
• The ToC doesn't show headings inside collapsed <details>

#5790 is related

Actual behavior

The ToC includes headings inside collapsed <details>. Clicking the ToC link does nothing.

Your environment

• Public source code: docs: overhauled member-ordering docs and types typescript-eslint/typescript-eslint#4873
• Public site URL: https://deploy-preview-4873--typescript-eslint.netlify.app/rules/member-ordering
• Docusaurus version used: 2.0.0-beta.18
• Environment name and version (e.g. Chrome 89, Node.js 16.4): Chrome 100, Node.js 14/16
• Operating system and version (e.g. Ubuntu 20.04.2 LTS): N/A

Self-service

• I'd be willing to fix this bug myself.