Mistake in reserve_time explanation in parser filter plugin

[mabrikan]

Describe the bug

I believe there is a mistake in the explanation for reserve_time property in parser filter plugin.

It is saying that when reserve_time: true, the time of the event is parsed from the specified parsing field (in that case, it is log).
However, it is the other way around (i.e. time of the event is kept and parsed time is discarded).

Link to the problematic documentation

https://docs.fluentd.org/filter/parser#reserve_time

Expected explanation

When reserve_time: true, the output is:

time:
2021-06-24 14:33:35.475115751 +0900 (It vary on parsed timestamp)

record:
{
  "user": 1
}

When reserve_time: false (default value), the output is:

time:
2021-06-01 00:00:00.000000000 +0900

record:
{
  "user": 1
}

Additional context

No response