update doc in build section (#56686)
Summary:
Why:
To keep VS version always updated in README
1. update VS version link in CI. It's more convenient for my PR robot to update the version in README once the VS in CI is updated. and permlink isn't stable.
2. Move `building on legacy code` to development tips. The table is big and it looks the REAMD not updated at the first sight.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/56686
Reviewed By: janeyx99
Differential Revision: D28272060
Pulled By: samestep
fbshipit-source-id: 4bb879ea2914cc8bcd68343a9ed230418e1f9268
