Update README to link matlab implementation.

README.md

@@ -9,6 +9,8 @@ Bamdev Mishra, N. T. V. Satya Dev, Hiroyuki Kasai, Pratik Jawanpuria. [Manifold
 
 The factory file is in compatible with the Pymanopt toolbox and can be easily integrated by placing it in the `pymanopt/manifolds/` folder (As of the Pymanopt's release `7f7a022 origin/dev` ). A helper file has been provided in the `helpers` directory explaining the usage of factory file.
 
+For MATLAB implementation checkout `matlab` branch.
+
 ## NOTE
 
 For GPU based acceleration (cupy), set the environment variable `USE_GPU_OPT` to `1`