Document removal of astro:content usage

src/content/docs/en/guides/upgrade-to/v5.mdx

@@ -288,9 +288,23 @@ Decide if charset=utf-8 should not be set for md/mdx pages by default
 
 Stuff!
 
-### Changed: `astro:content` can no longer be used on the client (PLT2118)
+### Changed: `astro:content` can no longer be used on the client
 
-Prevent use of `astro:content` on the client
+The `astro:content` module can no longer be used on the client. It was never intentionally exposed for client usage, leading to some developers to use it without realizing the limitations and bloat to client bundles.
+
+If currently using in the client, consider instead passing the data you need through properties to your client components:
+
+```astro
+---
+import { getCollection } from 'astro:content';
+import ClientComponent from '../components/ClientComponent';
+
+const posts = await getCollection('blog');
+const postsData = posts.map(post => post.data);
+---
+
+<ClientComponent posts={postsData} />
+```
 
 #### What should I do?