Fix typo datatime to datetime.

[akazeakari]

📖 Documentation

see https://qlib.readthedocs.io/en/latest/reference/api.html#qlib.workflow.task.utils.TimeAdjuster.shift

Shift the datatime of segment

The word datatime here should refer to the data type datetime.

And by searching, see

qlib/qlib/data/data.py

Line 619 in 155c17f

# If the underlaying provides the data not in datatime formmat, we'll convert it into datetime format

Here datatime should refer to the data type datetime, and formmat should be spelled as format.