add details in readme

            default:

                logging: true

```

## Details

There are 2 classes you may use :

* `Data\DbalLogTime\DbalLogger` extends the default dbal logger, adding an addtitionnal log line at the end of the query, which displays the execution time

* `Data\DbalLogTime\Params\DbalLogger` re-implements the logger to add the execution time in a `_duration` element in the parameters array. The query is therefore logged after it was executed