zinit | fast Zsh plugin manager with clean fpath | Command Line Interface library

I'm using OHMYZSH but I'm thinking about building a minimal configuration to Zsh.

So here's the problem. Ohmyzsh has special behaviour for completion. For example: if I'm in my Home Directory and type cd mus and hit a TAB it will expand to cd Music, even I'm typing the sentence with small letters.

I've founded this:

Have zsh return case-insensitive auto-complete matches, but prefer exact matches

Which is my problem but on the contrary. I want to get case insensitive without install OHMYZSH.

Looking at the OHMYZSH structure, I've found this:

. ├── ./cache

├── ./CODE_OF_CONDUCT.md

├── ./CONTRIBUTING.md

├── ./custom

├── ./lib

├── ./LICENSE.txt

├── ./log

├── ./oh-my-zsh.sh

├── ./plugins

├── ./README.md

├── ./templates

├── ./themes

└── ./tools

8 directories, 5 files

Inside the lib folder, there are some config files.

lib

├── bzr.zsh

├── clipboard.zsh

├── cli.zsh

├── compfix.zsh

├── completion.zsh

├── correction.zsh

├── diagnostics.zsh

├── directories.zsh

├── functions.zsh

├── git.zsh

├── grep.zsh

├── history.zsh

├── key-bindings.zsh

├── misc.zsh

├── nvm.zsh

├── prompt_info_functions.zsh

├── spectrum.zsh

├── termsupport.zsh

└── theme-and-appearance.zsh

0 directories, 19 files

I've already tried to source the completion.zsh using Zinit(plugin manager for ZSH which enables load some OHMYZSH stuff) without success. I don't know what is the correct file for the behaviour I want.

This is my config: