Add nin/nins pronouns

[DysphoricUnicorn]

Thanks for contributing! Please check the following things before submitting your PR :)

• [ ] PR message includes a link to the relevant issue(s) 💁‍♀️🖇️🧾
• [x] Commit messages are well-formatted (please follow this guide) 📝📐
• [x] New features have test coverage 📋☑️☑️☑️
• [x] The app boots and pronoun pages are served correctly (try lein ring server) 👩‍💻🚀