update feature list text

Author: swithek

README.md

@@ -10,10 +10,9 @@
 - Type parameters
 - Item expiration and automatic deletion
 - Automatic expiration time extension on each `Get` call
-- `Loader` interface that may be used to load/lazily initialize missing cache
-- Thread Safe
-items
-- Event handlers (insertion and eviction)
+- `Loader` interface that may be used to load/lazily initialize missing cache items
+- Thread safety
+- Event handlers (insertion, update, and eviction)
 - Metrics
 
 ## Installation