Rich Text in Firebase

I am creating a flashcards application for iOS and Android. I am trying to create content first and then hire engineers to help with porgramming. In order to create content I understood the basics of Firebase and how data is stored. The only problem is I want my Flashcard data (frontside and backside) to have Formatted text. bold, italics, highlighted text etc., which i will use later in the app to display rich text.

But how to go forward with this? A team of content creators are working in this project and how do i instruct them to type the content which can be used to convert into producible rich content?