fix: word misspelling in about-yoga.md (#1698)

Summary: Pull Request resolved: #1698

Reviewed By: joevilches

Differential Revision: D63059081

Pulled By: realsoelynn

fbshipit-source-id: 73d6d10685c7b4ddef828f17b7113f314397f90d

website/docs/about-yoga.md

@@ -10,4 +10,4 @@ Yoga is an embeddable layout system used in popular UI frameworks like React Nat
 
 Yoga supports a familiar subset of CSS, mostly focused on Flexbox. This gives users a familiar model, and enables sharing code between native platforms and the browser.
 
-Yoga is written in C++, with a public C API. This allows Yoga to be used by a wide variety of languages, via both offficial and unofficial bindings.
+Yoga is written in C++, with a public C API. This allows Yoga to be used by a wide variety of languages, via both official and unofficial bindings.