Revise README for V7 updates and breaking changes

Updated README to reflect new features in V7 and clarify migration to ESM.

README.md

@@ -12,9 +12,10 @@ This action provides the following functionality for GitHub Actions users:
 - Registering problem matchers for error output
 - Configuring authentication for GPR or npm
 
-## Breaking changes in V7
+## What's new in V7
 
-- **Migrated to ESM** to enable support for the latest `@actions/*` package versions.
+The V7 edition of the action includes:
+- Migrated action internals to ESM for compatibility with latest `@actions/*` packages. No changes to action inputs, outputs, or behavior.
 
 ## Breaking changes in V6