Add missing getting started paragraph
Add missing getting started paragraph

Summary: Noticed that there was an orphaned "First ...".

Reviewed By: mihaelao

Differential Revision: D5293176

fbshipit-source-id: 3ff8c9f467df23984e93fd4dc47c01430dc3edfc

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