Environment - Add guide to install Zsh and powerlevel10k

[umar-anzar]

• Shell & Terminal:
  - Zsh with Powerlevel10k: root/environment/shell/zsh-powerlevel10k.md

sudo apt update && sudo apt upgrade
sudo apt install zsh
reopen terminal
sh -c "$(curl -fsSL https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

powerlevel10k
sudo apt install fontconfig
fc-cache -fv
git clone --depth=1 https://github.com/romkatv/powerlevel10k.git ~/powerlevel10k
echo 'source /powerlevel10k/powerlevel10k.zsh-theme' >>/.zshrc
source ~/.zshrc