extensions/typescript-language-features/src/languageFeatures/tsconfig.ts/TsconfigLinkProvider/getExtendsLink
class TsconfigLinkProvider:	private getExtendsLink(document: vscode.TextDocument, root: jsonc.Node): vscode.DocumentLink | undefined {
		const extendsNode = jsonc.findNodeAtLocation(root, ['extends']);
		if (!this.isPathValue(extendsNode)) {
			return undefined;
		}

		if (extendsNode.value.startsWith('.')) {
			return new vscode.DocumentLink(
				this.getRange(document, extendsNode),
				vscode.Uri.file(join(dirname(document.uri.fsPath), extendsNode.value + (extendsNode.value.endsWith('.json') ? '' : '.json')))
			);
		}

		const workspaceFolderPath = vscode.workspace.getWorkspaceFolder(document.uri)!.uri.fsPath;
		return new vscode.DocumentLink(
			this.getRange(document, extendsNode),
			vscode.Uri.file(join(workspaceFolderPath, 'node_modules', extendsNode.value + (extendsNode.value.endsWith('.json') ? '' : '.json')))
		);
	}