src/vs/base/common/htmlContent.ts/isEmptyMarkdownString
export function isEmptyMarkdownString(oneOrMany: IMarkdownString | IMarkdownString[] | null | undefined): boolean {
	if (isMarkdownString(oneOrMany)) {
		return !oneOrMany.value;
	} else if (Array.isArray(oneOrMany)) {
		return oneOrMany.every(isEmptyMarkdownString);
	} else {
		return true;
	}
}