Create a footer on main docs site

[vfdev-5]

📚 Documentation

It would be helpful to enable a footer on the docs site: https://pytorch.org/ignite/ where we can keep current mentions like

• © Copyright 2021, PyTorch-Ignite Contributors.
• Built with Sphinx using a theme provided by Read the Docs.

and should place a badge from https://www.netlify.com/press/#badges . For example, this one :

I assume that we can tweak footer part from https://github.com/pytorch/ignite/blob/master/docs/source/_templates/layout.html#L304

@trsvchn could you please help us with this improvement ?

[trsvchn]

@vfdev-5 Absolutely! I would love to do that!

[vfdev-5]

Thanks a lot @trsvchn !