update readme

Author: coltenwebb

hie-compat/README.md

@@ -4,13 +4,17 @@ Mainly a backport of [HIE
 Files](https://gitlab.haskell.org/ghc/ghc/-/wikis/hie-files) for ghc 8.6, along
 with a few other backports of fixes useful for `ghcide`
 
+Also includes backport of record-dot-syntax support to 9.2.x
+
 Fully compatible with `.hie` files natively produced by versions of GHC that support
 them.
 
 **THIS DOES NOT LET YOU READ HIE FILES WITH MISMATCHED VERSIONS OF GHC**
 
 Backports included:
 
+https://gitlab.haskell.org/ghc/ghc/-/merge_requests/8589
+
 https://gitlab.haskell.org/ghc/ghc/-/merge_requests/4037
 
 https://gitlab.haskell.org/ghc/ghc/-/merge_requests/4068