message: put npm install command within quotes in the doc
diff: @@ -88,7 +88,7 @@ npm install --save-dev babel-jest babel-core regenerator-runtime
  > with the following command:
  >
  > ```
  -> npm install --save-dev babel-jest babel-core@^7.0.0-0 @babel/core regenerator-runtime
  +> npm install --save-dev babel-jest 'babel-core@^7.0.0-0' @babel/core regenerator-runtime
  > ```
  _Note: Explicitly installing `regenerator-runtime` is not needed if you use
  