[Documentation]: The description of the incremental backup method is misleading

[ljfuyuan]

What version of Badger is the target?

V4.2.0

Documentation.

The Backup method is misleading in its description of incremental backup. The description says returns a timestamp (version) indicating the version of last entry that is dumped, which after incrementing by 1 can be passed into later invocation to generate incremental backup

But to actually achieve incremental backup, you need to pass the value directly without +1 first

Additional information.

When I test incremental backup, if I add 1 to the version returned by Backup(writer,0), some data will always be missed. If I use the version directly, I can get all the data correctly.