[migration guide] - RSS has changed (withastro#1087)

Co-authored-by: Chris Swithinbank <[email protected]>

src/pages/en/migrate.md

@@ -36,19 +36,17 @@ const canonicalURL = Astro.canonicalURL;
 const canonicalURL = new URL(Astro.url.pathname, Astro.site);
 ```
 
-## Astro 1.0 Beta
+## Migrate to v1.0.0-beta
 
 On April 4, 2022 we released the Astro 1.0 Beta! 🎉
 
-**We do not plan to make any more breaking changes during this beta period, leading up to the official v1.0.0 release (planned for [late July, 2022](https://astro.build/blog/astro-1-release-update/)).**
-
-If any breaking changes must be made, we will call them out in this section.
+If you are coming from v0.25 or earlier, make sure you have read and followed the [v0.26 Migration Guide](#migrate-to-v026) below, which contained several major breaking changes.
 
-## Migrate to v1.0.0-beta.0
+The `v1.0.0-beta.0` release of Astro contained no breaking changes. Below are small changes that were introduced during the beta period.
 
-The `v1.0.0-beta.0` release of Astro contained no breaking changes.
+### Changed: RSS Feeds
 
-If you are coming from v0.25 or earlier, make sure you have read and followed the [v0.26 Migration Guide](#migrate-to-v026) below, which contained several major breaking changes.
+RSS feeds should now be generated using the `@astrojs/rss` package, as described in our [RSS guide](/en/guides/rss/).
 
 ## Migrate to v0.26
 ### New Configuration API