Typo in Citation on Readthedocs

[patrickmineault]

There's a type in the citation on readthedocs, which means I can't copy and paste the citation into my reference manager (Zotero). Specifically, there's a missing end curly brace in the version number.

This is the line that causes the issue:

https://github.com/Epistimio/orion/blob/develop/README.rst?plain=1#L153