Deferred loading of the oh-my-zsh plugin for nvm, using zsh-defer, and loading of the current version based from .nvmrc. This speeds up shell startup time while still making sure that nvm is loaded when needed.

# ...
if ! zgen saved; then
    zgen oh-my-zsh
    zgen load romkatv/zsh-defer
    zgen load davidparsson/zsh-nvm-deferred
    zgen save
fi