Subscript and Superscript for Draftail Rich Text Editor

[johnnyporkchops]

Summary

For footnotes on in-progress and upcoming Wagtail table features, enabling Superscript in the Draftail Rich Text Editor would be a useful feature. This is NOT a blocker for those issues, however.

I believe it can be enabled without having to create a new React component. Unfortunately, it is not as simple as adding it to a whitelist, but definitely not as complicated as creating a whole new component like we did for Glossary items

The below SO post has the basic process for enabling it it to our version of Wagtail.
Also, according to this post, enabling RTE options becomes simpler with Wagtail 2.5. (We are currently on 2.2.1).
https://stackoverflow.com/questions/49264519/adding-superscript-to-draftail-in-wagtail-2-0

Use Case

This will be used in Wagtail custom table/chart builders in these issues:
Mock up ideas for a Wagtail page to replace the organizational chart #2877 (See linked related issues here as well)
Design a new table in Wagtail to display the 2020 congressional pre-primary reports info #3016 (See linked related issues here as well)

Who would benefit from this requested feature?

• FEC Content team
• Users, added content clarity