docs: update README

Author: dgp1130

README.md

@@ -1,5 +1,24 @@
 # Angular Universal
 
-## This repository has been moved to Angular CLI repo
+Angular Universal was a project to expand on the core APIs from Angular
+(platform-server) to enable developers to do server side rendering of Angular
+applications in a variety of scenarios.
 
-You can find the Angular CLI repo [here](https://github.com/angular/angular-cli).
+## This repository has been merged into the Angular CLI repo
+
+In version 17, Universal has been moved into the
+[Angular CLI repo](https://github.com/angular/angular-cli). Code has been
+refactored and renamed (mostly under
+[`@angular/ssr`](https://github.com/angular/angular-cli/tree/main/packages/angular/ssr/)
+now), but the core functionality and architecture is unchanged.
+
+Universal features such as server-side rendering and build-time prerendering are
+now directly supported in Angular CLI and do not require a separate integration
+with Universal.
+
+As a result, this repository is effectively in maintenance mode and is no longer
+accepting contributions. Improvements to Angular's SSR/prerendering tooling
+should be made against the [CLI repo](https://github.com/angular/angular-cli)
+directly. Universal versions under long-term support (LTS) are still maintained
+by the Angular team and will continue to receive security fixes until they fall
+out of LTS.