NH-4000 - added some highlights

Author: fredericDelaporte

releasenotes.txt

@@ -1,6 +1,14 @@
 Build 5.0.0
 =============================
 
+** Highlights
+    * IO bound methods have gained an async counterpart. Not intended for parallelism, make sure to await each
+      call before further interacting with a session and its queries.
+    * Strongly type DML operation (insert/update/delete) are now available as Linq extensions on queryables.
+    * Entities collections can be queried with .AsQueryable() Linq extension without being fully loaded.
+    * Reference documentation has been curated and completed, notably with a Linq section.
+      http://nhibernate.info/doc/nhibernate-reference/index.html
+
 ** Known BREAKING CHANGES from NH4.1.1.GA to 5.0.0
 
     NHibernate now targets .Net 4.6.1.