'brackets': Use one-based indexing
'brackets': Use one-based indexing

zsh arrays start at one, and this will make the next commit easier.

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