update release notes

Change-Id: Ida17b9d3da4d3a6489f62d2959379747a671fbab
Docs-Preview: https://skia.org/?cl=428982
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/428982
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Reviewed-by: Heather Miller <hcm@google.com>
Commit-Queue: Heather Miller <hcm@google.com>
Auto-Submit: Heather Miller <hcm@google.com>
diff --git a/RELEASE_NOTES.txt b/RELEASE_NOTES.txt
index 87b0d7e..42a3a3d 100644
--- a/RELEASE_NOTES.txt
+++ b/RELEASE_NOTES.txt
@@ -2,7 +2,11 @@
 
 This file includes a list of high level updates for each milestone release.
 
-  * Removed SkMatrix44
+* * *
+
+Milestone 94
+------------
+  *
 
 * * *
 
@@ -17,6 +21,8 @@
   * The default value of GrContextOptions::fReduceOpsTaskSplitting is now enabled.
     https://review.skia.org/419836
 
+  * Removed SkMatrix44
+
 * * *
 
 Milestone 92