Switch `fasd` -> `z.lua`

[nathanshelly]

https://github.com/skywind3000/z.lua - actively maintained and 10x faster (according to it's docs)

[nathanshelly]

Additional possibly useful context:

• timing/method comparison
• another alternative - https://github.com/agkozak/zsh-z

[nathanshelly]

Caveat: fasd supports tracking of files as well as directories which neither z.lua or zsh-z seem to do

[nathanshelly]

v could potentially replace the file access

[nathanshelly]

another interesting alternative (in Rust! 🦀) - https://github.com/ajeetdsouza/zoxide