Changed Usage to API. Added --save-dev to installation instructions

mpeyper · mpeyper · commit 32f5118751a9 · 2019-02-24T20:58:30.000+11:00
diff --git a/README.md b/README.md
@@ -114,10 +114,10 @@ describe('custom hook tests', () => {
 ## Installation
 
 ```sh
-npm install react-hooks-testing-library
+npm install --save-dev react-hooks-testing-library
 ```
 
-## Usage
+## API
 
 ### `renderHook(callback[, options])`
 
