Update README.md

README.md

@@ -45,6 +45,7 @@ You can use NeDB as an in-memory only datastore or as a persistent datastore. On
 
 * `filename` (optional): path to the file where the data is persisted. If left blank, the datastore is automatically considered in-memory only. It cannot end with a `~` which is used in the temporary files NeDB uses to perform crash-safe writes
 * `inMemoryOnly` (optional, defaults to false): as the name implies.
+* `timestampData` (optional, defaults to false): timestamp the insertion and last update of all documents, with the fields `createdAt` and `updatedAt`. User-specified values override automatic generation, usually useful for testing.
 * `autoload` (optional, defaults to false): if used, the database will
   automatically be loaded from the datafile upon creation (you don't
 need to call `loadDatabase`). Any command