docs: add install instructions for iOS (#781)

AngelTrinidad · web-flow · commit d8f9ca7b2f5c · 2021-07-08T15:48:30.000-04:00
diff --git a/README.md b/README.md
@@ -61,6 +61,7 @@ and
 
 ```bash
 yarn add react-native-fast-image
+cd ios && pod install
 ```
 
 ```jsx
