Add missing properties in option typedef

src/ol/source/VectorTile.js

@@ -44,6 +44,8 @@ import {createXYZ, extentFromProjection, createForProjection} from '../tilegrid.
  * @property {string} [url] URL template. Must include `{x}`, `{y}` or `{-y}`, and `{z}` placeholders.
  * A `{?-?}` template pattern, for example `subdomain{a-f}.domain.com`, may be
  * used instead of defining each one separately in the `urls` option.
+ * @property {number} [transition] A duration for tile opacity
+ * transitions in milliseconds. A duration of 0 disables the opacity transition.
  * @property {Array.<string>} [urls] An array of URL templates.
  * @property {boolean} [wrapX=true] Whether to wrap the world horizontally.
  * When set to `false`, only one world