collapse & table

https://github.com/Microsoft/TypeScript/issues/30034

GitHub collapse markdown

https://github.com/Mottie/GitHub-userscripts/wiki/GitHub-collapse-markdown

https://github.com/Mottie/GitHub-userscripts/wiki/GitHub-table-of-contents
https://github.com/Mottie/GitHub-userscripts/wiki/GitHub-collapse-in-comment

<details>
    <summary>Click to expand</summary>
    whatever
</details>

space line break & indent 4 space

demo

https://github.com/xgqfrms/WNAAIO/issues/1#issuecomment-474665079

    <details>
        <summary>Click to expand</summary>

    ```js
        console.log(`hello world!`);
    ```
    </details>

    console.log(`hello world!`);

ok

docs

https://daringfireball.net/projects/markdown/

https://github.com/search?o=desc&q=markdown&s=stars&type=Repositories

https://github.com/younghz/Markdown
https://younghz.github.io/Markdown/

email applications

https://github.com/adam-p/markdown-here
https://markdown-here.com/

online tools

https://dillinger.io/

blogs

https://blog.codinghorror.com/standard-markdown-is-now-common-markdown/