Atuin can import your history from your "old" history file
atuin import auto will attempt to figure out your shell (via $SHELL) and run
the correct importer
Unfortunately these older files do not store as much information as Atuin does, so not all features are available with imported data.
atuin import zsh
If you've set HISTFILE, this should be picked up! If not, try
HISTFILE=/path/to/history/file atuin import zsh
This supports both the simple and extended format
TODO