Reported accuracies may go outdated

[NicolasHug]

We report a bunch of tables with accuracies for the torchvision models, but some of them may be wrong (for example as reported in #313), or go out of date because the default weight may change (with improved accuracy).

To avoid duplicating the info in too many places it might be best to not report the accuracies directly in torchhub and instead refer to the acc table in torchvision (ideally with a search option for convenience?)