document more changes
diff --git a/WHATSNEW b/WHATSNEW
index da17d1c..44ebd72 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -143,3 +143,5 @@
 is not readable, or on archs (not yet supported) that forbid
 misaligned reads.
 
+added many compatibility and system-level interfaces, increasing the
+proportion of busybox that works with musl.