Improve component matching testing docs
Improve component matching testing docs

Summary: Improve component matching testing docs

Reviewed By: colriot

Differential Revision: D25637760

fbshipit-source-id: caa8fec8f208f1cf317c83a525672dd9cb1b6db3

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