Include better versions of a model when they are available in the model doc pages

@NielsRogge provided a great suggestion.

We could add a banner on top of Swin’s docs (and other models where this is applicable), to indicate we have a better model now, SwinV2. The same could be done for DETR, as Conditional DETR and Deformable DETR greatly improve the convergence and AP metrics.

We can start with the following:

• Swin
• DETR

And then expand to the other models. Or else, we can start with five such models (feel free to suggest more). When reviewing model PRs to transformers, we would just need to be mindful about this a bit so that we can suggest it accordingly to the contributors.

Cc: @osanseviero @nateraw

[sgugger]

I am very wary about this. If you start telling on the page of a model that have been developed by Org 1 that there is a better model developed by Org 2, they will get mad and we will then have unnecessary conflicts to handle.

For the same reason we stay away from benchmarks between frameworks/hardware, I would stay away from this.

[osanseviero]

We could just do it for papers that come from the same team (Swin => Swinv2), to promote upcoming work.

Sure, why not 😃 for those scenarios I think it’s ok to open small PRs updating the corresponding docstrings