typo on conda commands in pytorch.github.io/_get_started/previous-versions.md

[bbelgodere]

📚 Documentation

Looks like there are several typos in pytorch.github.io/_get_started/previous-versions.md regarding conda installs

While 1.10.1 and 1.10.0 have been compiled against Cuda 11.1 and 11.3 in the conda-forge pytorch channel Versions 1.9.1, 1.9.0, and 1.8.1 are only compiled against cuda 11.1

Either the following three sections need to be updated to require cudatoolkit=11.1 not cudatoolkit=11.3
https://pytorch.org/get-started/previous-versions/#linux-and-windows-4
https://pytorch.org/get-started/previous-versions/#linux-and-windows-6
https://pytorch.org/get-started/previous-versions/#linux-and-windows-8

or the additional packages need to uploaded to the conda-forge pytorch channel

I verified the available packages for conda via
https://anaconda.org/pytorch/pytorch/files?version=1.9.1
https://anaconda.org/pytorch/pytorch/files?version=1.9.0
https://anaconda.org/pytorch/pytorch/files?version=1.8.1

Thanks for all the hard work building great tools and keeping the documentation current...

[NeoKish]

#940 addresses issue for versions 1.8.1 and 1.9.0