docs: Added style key prefix convention
docs: Added style key prefix convention

Part of #306

zsh-users/zsh-syntax-highlighting,joshuarubin/dotfiles,phy1729/zsh-syntax-highlighting,danielshahaf/zsh-syntax-highlighting,joshuarubin/dotfiles,zsh-users/zsh-syntax-highlighting,x-way/zsh-syntax-highlighting,stuha/wbr-zsh,phy1729/zsh-syntax-highlighting,danielshahaf/zsh-syntax-highlighting-debian,m0vie/zsh-syntax-highlighting,x-way/zsh-syntax-highlighting,joshuarubin/dotfiles,psprint/zsh-syntax-highlighting,P71/zsh-syntax-highlighting,danielshahaf/zsh-syntax-highlighting-debian,P71/zsh-syntax-highlighting,joshuarubin/dotfiles,danielshahaf/zsh-syntax-highlighting,m0vie/zsh-syntax-highlighting,psprint/zsh-syntax-highlighting