Integrate the RichTextLabel editor plugin?

We have a set of plugins to make formatting and writing text easier in Godot 3.1. Should we integrate it to Godot slides? See https://github.com/GDquest/kickstarter-quest-3/tree/master/gdquest-godot-theme/addons

Start by reviewing the RichTextLabel editor plugins in the linked gdquest-godot-theme/addons directory and comparing them with the Godot slides project. Determine which plugin behavior is intended to be integrated and how integration would fit the project; done should mean the agreed plugin functionality works in Godot slides.

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