Updated readme for GLM 0.9.3.0 release

readme.txt

@@ -34,7 +34,14 @@ GLM is a header only library, there is nothing to build, just include it.
 #include <glm/glm.hpp>
 
 More informations in GLM manual:
-http://glm.g-truc.net/glm-0.9.2.pdf
+http://glm.g-truc.net/glm-0.9.3.pdf
+
+================================================================================
+GLM 0.9.3.0: 2011-XX-XX
+--------------------------------------------------------------------------------
+- Improved doxygen documentation
+- Added extension versioning
+- Removed many unused namespaces
 
 ================================================================================
 GLM 0.9.2.3: 2011-06-08