Fix callbacks not working

[zoriya]

The callbacks did not work (because the initial empty configuration was used instead of the user's).

I also added an option to disable vim.notify calls (I want to remove all unnecessary prints and having one after every file change was too much).

[edwestfieldjr]

Did these changes get forked into main? I'm still having the same issues with undo that I used to have... How do we reimplement?

[primeapple]

Feel free to try out the maintained fork https://github.com/okuuva/auto-save.nvim

It has a working implementation of callbacks via autocmd user events.

Disclaimer, I'm one of the authors.