docs: mention breaking change from vitejs#6901

docs/guide/migration.md

@@ -104,6 +104,9 @@ There are some changes which only affects plugin/tool creators.
 - [[#8178] feat!: migrate to ESM](https://github.com/vitejs/vite/pull/8178)
   - `formatPostcssSourceMap` is now async
   - `resolvePackageEntry`, `resolvePackageData` are no longer available from CJS build (dynamic import is needed to use in CJS)
+- [[#6901] fix: sequential injection of tags in transformIndexHtml](https://github.com/vitejs/vite/pull/6901)
+  - `transformIndexHtml` now gets the content modifed by other plugins
+  - The order of the tags injected by `transformIndexHtml` is now correct
 
 Also there are other breaking changes which only affect few users.