A userscript that adds a button to insert a details block into comments
A button is added to the issue/pull request comment toolbar.
Clicking the button will add a <details> block with the selected text inside.
Adding an "open" attribute to the details element will start with the container expanded. A hint using "not-open" is included and is ignored unless changed to "open".
A blank line is included after the summary to allow markdown elements to render properly inside of the details container (ref).