Summary:
When working on Dynamic Type, I accidentally referred to it as "Dynamic Text" in some of the documentation. This is just a minor cleanup bit.
## Changelog
[IOS] [FIXED] - Fix typo in documentation
Pull Request resolved: https://github.com/facebook/react-native/pull/36113
Test Plan: Non-functional change, no testing should be needed :-)
Reviewed By: javache
Differential Revision: D43184999
Pulled By: cortinico
fbshipit-source-id: ed057e48289ae6037637bacecb20b8dd58c1d8b5