## Description

Please include a concise summary of the change and which issue it fixes. 

Please also include relevant motivation and context, on a separate line.

Fixes # (issue)

## Type of change

Please delete options that are not relevant.

- [X] Bug fix (non-breaking change which fixes an issue)
- [X] Variable addition (adds a new variable or type string)
- [X] New feature (non-breaking change which adds functionality)
- [X] Breaking change (fix or feature that would cause existing functionality to not work as expected)
- [X] This change requires a documentation update

## Checklist

- [X] I have installed the repo [pre-commit hook](https://github.com/citation-style-language/schema/blob/master/CONTRIBUTING.md#pre-commit-hooks); if not, and I have modified any of the schema files, I have run trang and/or prettier on the files, per [CONTRIBUTING](https://github.com/citation-style-language/schema/blob/master/CONTRIBUTING.md)
- [X] I have performed a self-review of my own code
- [X] I have included suggested corresponding changes to the documentation (if relevant)
