[Identity] Updated the main changelog after releasing 1.4.0 (#16341)

sdk/identity/identity/CHANGELOG.md

@@ -68,6 +68,13 @@
 
 > With the plans for [third party cookies to be removed from browsers](https://docs.microsoft.com/azure/active-directory/develop/reference-third-party-cookies-spas), the **implicit grant flow is no longer a suitable authentication method**. The [silent SSO features](https://docs.microsoft.com/azure/active-directory/develop/v2-oauth2-implicit-grant-flow#getting-access-tokens-silently-in-the-background) of the implicit flow do not work without third party cookies, causing applications to break when they attempt to get a new token. We strongly recommend that all new applications use the authorization code flow that now supports single page apps in place of the implicit flow, and that [existing single page apps begin migrating to the authorization code flow](https://docs.microsoft.com/azure/active-directory/develop/migrate-spa-implicit-to-auth-code) as well.
 
+
+## 1.4.0 (2021-07-09)
+
+- With this release, we drop support for Node.js versions that have reached the end of life, like Node.js 8. Read our [support policy](https://github.com/Azure/azure-sdk-for-js/blob/main/SUPPORT.md) for more details.
+- Updated the default timeout of the first request of the IMDS MSI from half a second to three seconds to compensate for the slowness caused by `node-fetch` for initial requests in specific environments, like Kubernetes pods.
+- Upgraded `@azure/core-http` to version `^2.0.0`, and `@azure/core-tracing` to version `1.0.0-preview.12`.
+
 ## 1.3.0 (2021-04-05)
 
 ### Tracing Changes