Add write support for Transaction

src/objectliterals.jsdoc

@@ -346,6 +346,18 @@
  * @property {ol.Extent|undefined} bbox Extent to use for the BBOX filter.
  */
 
+/**
+ * @typedef {Object} olx.format.WFSWriteTransactionOptions
+ * @property {string} featureNS The namespace URI used for features.
+ * @property {string} featurePrefix The prefix for the feature namespace.
+ * @property {string} featureType The feature type name.
+ * @property {string|undefined} srsName SRS name. No srsName attribute will be
+ *     set on geometries when this is not provided.
+ * @property {string|undefined} handle Handle.
+ * @property {Array.<Object>} nativeElements Native elements. Currently not
+ *     supported.
+ */
+
 /**
  * @typedef {Object} olx.interaction.DoubleClickZoomOptions
  * @property {number|undefined} duration Animation duration in milliseconds. Default is `250`.