Update Quickstart guide for the Development Environment documentation.

[paaljoachim]

Updated version number for installing nvm.
I also added some additional information just above nvm install --lts command.

This is my first pull request.

[paaljoachim]

I actually would like to mention one more thing.
The Quick Start title for this documentation is "Quickstart" while for the https://developer.wordpress.org/block-editor/tutorials/create-block/ Create a block documentation we call it "Quick Start"
It would be nice to have consistency. To for both documentation use "Quickstart" or "Quick Start".

[mkaz]

@paaljoachim I created PR #28019 to update and standardize on "Quick Start"