feat: add changelog entry for "Workers Platform" roles

Author: danielrs

src/content/changelog/workers/2025-06-16-workers-platform-admin-role.mdx

@@ -0,0 +1,22 @@
+---
+title: Introducing "Workers Platform" set of roles
+description: Workers Platform admin and read-only roles to cover more use-cases.
+date: 2025-06-16T00:00:00Z
+---
+
+The role "Workers Admin" has been renamed to "Workers Platform Admin". This change
+was introduced to account for the fact that role granted access to more than just
+Workers, and it was a point of confusion to many customers.
+
+Additionally, we added the "Workers Platform (Read-only)" role. It's similar to the
+admin role, but the only difference is that it has all the create/update/delete
+permissions stripped out.
+
+See the updated and added roles here:
+
+https://developers.cloudflare.com/fundamentals/manage-members/roles/
+
+### How are you affected?
+
+If you're using the old role name "Workers Admin" to talk to our API, you should
+update all your references to use the new name "Workers Platform Admin".