Updating the changelog for React Developer Tools

Updating the changelog for React Developer Tools to make it explicit about iframes

CHANGELOG.md

@@ -6,7 +6,7 @@ This release has the following improvements:
  - Better structure of the Apollo Client hooks for the sample addon component in the `carbon-addons-devenv` package.
  - Restructured documentation, now including an overview diagram. Improved guidance for customization, both for creating custom pages and for customizing the Case Overview. Improved guidance about creating GraphQL queries.
  - The provision of a lightweight mock GraphQL service that serves data from the file system and can be used within this sandboxed environment for testing purposes. You can use the mock GraphQL service to test your custom components before production GraphQL queries development is completed.
- - Enablement of the React Development Tools browser extension to view the composition of React JavaScript components on a web page.
+ - Enablement of the React Development Tools browser extension to view the composition of React JavaScript components on web page with iframes.
  - The provision of a tool that shows a breakdown of the generated JavaScript files in terms
 of how much footprint (size in KB) each third-party library contributes to their overall size.
 - The introduction of `index_latest` files as a mechanism to convey the most up-to-date-template for index files. You can diff `index_latest` files with your verion of the `index.js` or `index.scss` files to see any differences in the underlying directory structure.