support install with "lts", "latest" keywords

[hhheroo]

I wrote a plugin called nodenv-lts-install, which can install Node.js using some keywords.

# install current latest node version
nodenv install latest

# install current latest lts node version
nodenv install lts

# install latest node22
nodenv install jod
# install latest node20
nodenv install iron

# install latest node20.x.x
nodenv install 20
# install latest node20.1.x
nodenv install 20.1
# install node20.1.0
nodenv install 20.1.0

Since I am not familiar with shell scripting, I developed it using JavaScript. I am looking for someone who can help me translate it to shell script.