Update release notes for release of 0.4.0-alpha.1

Author: abelbraaksma

release-notes.txt

@@ -1,14 +1,15 @@
 
 Release notes:
 0.4.x (unreleased)
-    - BREAKING CHANGE: most null arguments now raise ArgumentNullException instead of NullReferenceException, #127
+    - fix documentation
+	
+0.4.0-alpha.1
+    - fixes not calling Dispose for 'use!', 'use', or `finally` blocks #157 (by @bartelink)
+    - BREAKING CHANGE: null args now raise ArgumentNullException instead of NullReferenceException, #127
     - adds `let!` and `do!` support for F#'s Async<'T>, #79, #114
     - adds TaskSeq.takeWhile, takeWhileAsync, takeWhileInclusive, takeWhileInclusiveAsync, #126 (by @bartelink)
     - adds AsyncSeq vs TaskSeq comparison chart, #131
     - removes release-notes.txt from file dependencies, but keep in the package, #138
-
-0.3.1 (unreleased)
-    - fixes not calling Dispose for 'use!', 'use', or `finally` blocks in `try`...`finally` #157
 
 0.3.0
     - internal renames, improved doc comments, signature files for complex types, hide internal-only types, fixes #112.