[RFC] MXNet website improvements

[sandeep-krishnamurthy]

Description

This issue is being created to gather:

1. All the new feature requests/suggestions for MXNet website improvements and changes.
2. Current we have 40 open issues tagged "Website" - https://github.com/apache/incubator-mxnet/issues?q=is%3Aissue+is%3Aopen+label%3AWebsite , if there are any other issues that you face, please comment.

If your feature request/issue is already listed, please +1.

All the feature requests and issues listed in this issue will be triaged and projects will be created to improve MXNet website experience.

[ChaiBapchya]

Another issue: Anchor tags are shifted.
Anchor tags exist, but they don't work properly. They are shifted by certain margin [potentially getting hidden by the header]
For ex:

1. Go to contribute page : https://mxnet.apache.org/community/contribute.html
2. Select a specific anchor : Setup MXNet for Development [https://mxnet.apache.org/community/contribute.html#setup-mxnet-for-development]
3. It takes you here

But it's supposed to show you this

This looks like an easy fix and improves usability as anchor tags will start behaving correctly [rather than user having to scroll up to adjust the screen].

[ys2843]

Looks like a bug, moved it to another issue. Will fix this

[ChaiBapchya]

Another bug I had found was table of content leaking over to the footer
Maybe you can prioritize this one too #16349

Thanks @ys2843

[ChaiBapchya]

#18693

• Clipped table of contents
• Missing copy button

[ChaiBapchya]

#18719

• beta.mxnet.io redirects to mxnet.incubator.apache.org/ landing page [instead of specific API]
• google index needs to be updated to point to mxnet official API page [instead of beta site]