fix pip install archive url (pytorch#1355)

target cuda version was wrong

Author: rollingman1

_get_started/previous-versions.md

@@ -292,7 +292,7 @@ pip install torch==1.10.1+rocm4.1 torchvision==0.11.2+rocm4.1 torchaudio==0.10.1
 pip install torch==1.10.1+rocm4.0.1 torchvision==0.10.2+rocm4.0.1 torchaudio==0.10.1 -f https://download.pytorch.org/whl/torch_stable.html
 
 # CUDA 11.1
-pip install torch==1.10.1+cu111 torchvision==0.11.2+cu111 torchaudio==0.10.1 -f https://download.pytorch.org/whl/cu113/torch_stable.html
+pip install torch==1.10.1+cu111 torchvision==0.11.2+cu111 torchaudio==0.10.1 -f https://download.pytorch.org/whl/cu111/torch_stable.html
 
 # CUDA 10.2
 pip install torch==1.10.1+cu102 torchvision==0.11.2+cu102 torchaudio==0.10.1 -f https://download.pytorch.org/whl/cu102/torch_stable.html