Add the new SVGs feature from the template README to the root README (facebook#5374)

Author: neo

README.md

@@ -144,6 +144,7 @@ The [User Guide](https://github.com/facebook/create-react-app/blob/master/packag
 - [Adding a CSS Modules Stylesheet](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#adding-a-css-modules-stylesheet)
 - [Post-Processing CSS](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#post-processing-css)
 - [Adding Images, Fonts, and Files](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#adding-images-fonts-and-files)
+- [Adding SVGs](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#adding-svgs)
 - [Using the `public` Folder](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#using-the-public-folder)
 - [Using Global Variables](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#using-global-variables)
 - [Adding Bootstrap](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#adding-bootstrap)