Install
This is the repository archive. It installs, but the folder name will carry the branch suffix and updates will not flow.
Install straight from GitHub with WP-CLI:
wp plugin install https://github.com/curtismchale/darkmode-toggle/archive/refs/heads/master.zipNo built-in updater. New versions won't appear under Dashboard → Updates. Install new releases yourself, or let Git Updater track the repository.
This does not actually add darkmode to your site. It does provide a toggle and a class to target so that you can write a bit of CSS yourself for your theme to make it all work.
It does store the preference of the user in Local Storage and uses that to keep their selection around.
It does detect if their system is set to darkmode already and if so, shows them darkmode on the site by adding the class listed below.
For your CSS target .darkmode--activated on your body class.
That is all.