Replace google closure syntax = with brackets around name

src/ol/layer/VectorTile.js

@@ -76,13 +76,13 @@ import {assign} from '../obj.js';
  * property on the layer object; for example, setting `title: 'My Title'` in the
  * options means that `title` is observable, and has get/set accessors.
  *
- * @param {Options=} opt_options Options.
+ * @param {Options} [opt_options] Options.
  * @extends {BaseVectorLayer<import("../source/VectorTile.js").default>}
  * @api
  */
 class VectorTileLayer extends BaseVectorLayer {
   /**
-   * @param {Options=} opt_options Options.
+   * @param {Options} [opt_options] Options.
    */
   constructor(opt_options) {
     const options = opt_options ? opt_options : {};