Prints a script to check whether or not the Customizer is supported, and apply either the no-customize-support or customize-support class to the body.
You can use above key combination to trigger the associated snippet for this function in the WordPress Snippets for Visual Studio Code extension. You can also use this shortcut to search for this function on this website.
This function MUST be called inside the body tag.
Ideally, call this function immediately after the body tag is opened. This prevents a flash of unstyled content.
It is also recommended that you add the "no-customize-support" class to the body tag by default.