restyle transition-key-types.md
restyle transition-key-types.md

Summary:
The information within transition-key-types.md has already been through the review cycle and has been deemed ready for restyling.

This diff contains restyling of the content, including formatting, spelling, grammar, and link checking.

Differential Revision: D33818394

fbshipit-source-id: 8fc679c9095138182f576002be63cfa0560f63bb

facebook/litho,facebook/litho,facebook/litho,facebook/litho,facebook/litho,facebook/litho