Add magma for CUDA 10.1 to Windows docs

Summary: Pull Request resolved: pytorch#19914

Differential Revision: D15123029

Pulled By: soumith

fbshipit-source-id: a3d4b498a763e1a9829896d44211be00400ec39d

docs/source/notes/windows.rst

@@ -19,7 +19,7 @@ MKL and MAGMA. Here are the steps to build with them.
     7z x -aoa mkl_2018.2.185.7z -omkl
 
     REM Download MAGMA files
-    REM cuda100 is also available for `CUDA_PREFIX`. There are also 2.4.0 binaries for cuda80/cuda92.
+    REM cuda100/cuda101 is also available for `CUDA_PREFIX`. There are also 2.4.0 binaries for cuda80/cuda92.
     REM The configuration could be `debug` or `release` for 2.5.0. Only `release` is available for 2.4.0.
     set CUDA_PREFIX=cuda90
     set CONFIG=release