extensions/markdown-language-features/src/features/foldingProvider.ts/MarkdownFoldingProvider/getFoldingRangeKind
class MarkdownFoldingProvider:	private getFoldingRangeKind(listItem: Token): vscode.FoldingRangeKind | undefined {
		return listItem.type === 'html_block' && listItem.content.startsWith('<!--')
			? vscode.FoldingRangeKind.Comment
			: undefined;
	}