This QCubed plugin lets you work with the CKEditor javascript text editor, which creates a full HTML editor in a web page.
This plugin is just for the PHP interface to CKEditor. You must also install the CKEditor library, which fortunately is installable via Composer. The directions below show you how to install both.
To install, execute the following on the command line from your main install directory:
composer require qcubed-4/plugin-ckeditor
composer require ckeditor/ckeditor