Colorlib updates

This host answers update checks for Colorlib WordPress themes and plugins that
are distributed outside WordPress.org, using the Update URI mechanism WordPress
added in 6.1.

  GET /theme/{slug}.json
  GET /plugin/{slug}.json

Your site sends, and this host stores: the product and version installed, your
WordPress and PHP versions, your locale, whether the install is multisite, and a
site identifier. That identifier is a one-way hash of your home URL salted with
your own install's AUTH_SALT — it is stable for your site and cannot be turned
back into a URL here. No IP address, site name, e-mail address or personal data
is sent or stored. It exists so that a count of installs is a count of sites
rather than a count of requests.

Themes can switch the whole thing off with the unapp_check_for_updates filter,
which also switches off update notifications — there is no way to be told about
a release without asking for it.