extensions/markdown-language-features/src/preview/documentRenderer.ts/MdDocumentRenderer/renderBody
class MdDocumentRenderer:	public async renderBody(
		markdownDocument: vscode.TextDocument,
		resourceProvider: WebviewResourceProvider,
	): Promise<MarkdownContentProviderOutput> {
		const rendered = await this.engine.render(markdownDocument, resourceProvider);
		const html = `<div class="markdown-body" dir="auto">${rendered.html}<div class="code-line" data-line="${markdownDocument.lineCount}"></div></div>`;
		return {
			html,
			containingImages: rendered.containingImages
		};
	}