[Feature Request] Optimize parameters on data after a certain date/time

[kuroahna]

When exporting the anki collection and using fsrs4anki_optimizer to optimize the parameters on the revlog, the optimizer will use all time series data in the revlog. I think this is good since we need lots of data to get accurate results. However, I have used Anki wrong in the past where my retention rate would be really low, like 60-70%. Only recently I have fixed the issue and my retention rate in Anki is around 80-85%. However, since fsrs4anki_optimizer uses the whole revlog, it will include the data from when I reviewed cards poorly, meaning the parameters returned will be skewed, and hence there will be a bias to give short intervals

It would be nice if we can optionally specify a certain date for when the optimizer will start processing the data, such as

revlog_start_date = "2022-04-01"

Otherwise, if not specified (such as a default value of None), it will use the whole revlog data

[L-M-Sherlock]

The latest version has supported it.