Update updating-to-new-releases.md

Related to facebook#6140

docusaurus/docs/updating-to-new-releases.md

@@ -8,7 +8,8 @@ Create React App is divided into two packages:
 - `create-react-app` is a global command-line utility that you use to create new projects.
 - `react-scripts` is a development dependency in the generated projects (including this one).
 
-You almost never need to update `create-react-app` itself: it delegates all the setup to `react-scripts`.
+When you run `npx create-react-app my-app` it automatically installs the latest version of Create React App.  
+> If you've previously installed `create-react-app` globally via `npm install -g create-react-app`, we recommend you uninstall the package using `npm uninstall -g create-react-app` to ensure that `npx` always grabs the latest version.
 
 When you run `create-react-app`, it always creates the project with the latest version of `react-scripts` so you’ll get all the new features and improvements in newly created apps automatically.