Remove references to _.

now.js

@@ -5,15 +5,14 @@ import root from './_root.js';
  * the Unix epoch (1 January 1970 00:00:00 UTC).
  *
  * @static
- * @memberOf _
  * @since 2.4.0
  * @category Date
  * @returns {number} Returns the timestamp.
  * @example
  *
- * _.defer(function(stamp) {
- *   console.log(_.now() - stamp);
- * }, _.now());
+ * defer(function(stamp) {
+ *   console.log(now() - stamp);
+ * }, now());
  * // => Logs the number of milliseconds it took for the deferred invocation.
  */
 const now = () => root.Date.now();