extensions/markdown-language-features/src/commands/openDocumentLink.ts/OpenDocumentLinkCommand/tryRevealLine
class OpenDocumentLinkCommand:	private static async tryRevealLine(engine: MarkdownEngine, editor: vscode.TextEditor, fragment?: string) {
		if (fragment) {
			const toc = new TableOfContentsProvider(engine, editor.document);
			const entry = await toc.lookup(fragment);
			if (entry) {
				const lineStart = new vscode.Range(entry.line, 0, entry.line, 0);
				editor.selection = new vscode.Selection(lineStart.start, lineStart.end);
				return editor.revealRange(lineStart, vscode.TextEditorRevealType.AtTop);
			}
			const lineNumberFragment = fragment.match(/^L(\d+)$/i);
			if (lineNumberFragment) {
				const line = +lineNumberFragment[1] - 1;
				if (!isNaN(line)) {
					const lineStart = new vscode.Range(line, 0, line, 0);
					editor.selection = new vscode.Selection(lineStart.start, lineStart.end);
					return editor.revealRange(lineStart, vscode.TextEditorRevealType.AtTop);
				}
			}
		}
	}