DOC: backport doc build fix from 1.7, tweak link (#47349)
Summary:
xref gh-46927 to the 1.7 release branch
This backports a fix to the script to push docs to pytorch/pytorch.github.io. Specifically, it pushes to the correct directory when a tag is created here. This issue became apparent in the 1.7 release cycle and should be backported to here.
Along the way, fix the canonical link to the pytorch/audio documentation now that they use subdirectories for the versions, xref pytorch/audio#992. This saves a redirect.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47349
Reviewed By: zhangguanheng66
Differential Revision: D25073752
Pulled By: seemethere
fbshipit-source-id: c778c94a05f1c3e916217bb184f69107e7d2c098
