Now you can add the phonetic support in the Atto text editor using Ruby/furigana plugin for atto.
The plugin contains an Atto toolbar button that simplifies annotating text with phonetic information – select some text, click the button and add the pronunciation of the text in question.
However as of now the plugin has a soft requirement of MDL-50868 (https://tracker.moodle.org/browse/MDL-50868) – you can create ruby tags with this and they’ll be stored in the DB okay, but HTMLPurifier will nuke them before they get to the browser. So it is kept in the experimental category in the Moodle plugins database. Whenever it is cleared of the dependency then it will be moved to the Atto plugins category.
You can download the current version of the Ruby plugin for atto from https://moodle.org/plugins/view/atto_ruby
Thanks Jetha Chan for submitting another superb plugins for the atto text editor.