The doc of `CocoDetection()` and `CocoCaptions()` should say "You must install `pycocotools`."

[hyperkai]

📚 The doc issue

The doc of CocoDetection() and CocoCaptions() says below:

It requires the COCO API to be installed.

But COCO API doesn't work because it's outdated.

Suggest a potential alternative/fix

So, the doc should say as shown below:

You must install pycocotools, e.g. pip install pycocotools, conda install conda-forge::pycocotools, etc. *Don't use COCO API because it doesn't work because it's outdated.

[NicolasHug]

Thanks @hyperkai , that's fair - would you mind submitting a PR for this?