change doxygen location in readme to new github location

Readme.txt

@@ -107,7 +107,7 @@ Get Doxygen from http://www.doxygen.org & Graphviz from http://www.graphviz.org.
 See section "Documentation build" below on how to automate documentation
 generation as part of the build process.
 
-The documentation is also available online at http://cadaver.homeftp.net/urho3d
+The documentation is also available online at http://urho3d.github.io/documentation/
 
 
 Building prerequisites
@@ -548,4 +548,4 @@ V1.1    - Object and scene model refactoring.
         - Added OpenGL and cross-platform support.
         - Switched to kNet library for networking.
 
-V1.0    - Original release.
+V1.0    - Original release.