docs: update README based on CR feedback

Author: ericapisani

README.md

@@ -42,11 +42,13 @@ by targeting the `/_next/image/*` route:
     X-Test = 'foobar'
 ```
 
-## Disabling `ipx`
+## Disabling included image loader
 
-If you wish to disable the use of the `ipx` package, set the `DISABLE_IPX` environment variable to `true`. Please note that some requests to `/_next/image/*` may fail unless an image loader, such as Cloudinary or Imgix, is specified as a replacement for `ipx`. 
+If you wish to disable the use of the image loader which is bundled into the runtime by default, set the `DISABLE_IPX` environment variable to `true`. 
 
-See the [Next.js documentation](https://nextjs.org/docs/api-reference/next/image#built-in-loaders) for options.
+This should only be done if the site is not using `next/image` or is using a different loader (such as Cloudinary or Imgix).
+
+See the [Next.js documentation](https://nextjs.org/docs/api-reference/next/image#built-in-loaders) for image loader options.
 
 ## Next.js Middleware on Netlify