Added description of 3.0.4 release.

README.md

diff --git a/README.md b/README.md
index 9414c14..830d494 100644
--- a/README.md
+++ b/README.md
@@ -6,8 +6,9 @@
 application development.  It provides a simple, platform-independent API for
 creating windows and contexts, reading input, handling events, etc.
 
-Version 3.0.4 is *not yet described*.  As this is a patch release, there are no
-API changes.
+Version 3.0.4 adds better support for custom build environments and fixes for
+a large number of bugs that together affect all supported platforms.  As this is
+a patch release, there are no API changes.
 
 If you are new to GLFW, you may find the
 [introductory tutorial](http://www.glfw.org/docs/latest/quick.html) for GLFW