time.elapsed of task always equal to 0 - its time.started

the `time.elapsed` of task is always equal to - its.time.started, no matter the timer is running or stopped. I hope task's time.elapsed is same defined as #11 .

P.S. in the doc: https://onury.io/tasktimer/api/#TaskTimer#remove , since task got no `name` attribute, maybe using `id` is more accurate. :)