[DOC] Update Website to Add Prerequisites for GPU pip install

[barry-jin]

Description

This PR will update the website to put CUDA, cuDNN and NCCL installation requirements ahead to well-inform the user of these prerequisites if they want to use pip to install MXNet1.8 or higher version. Also, catch exceptions for missing libraries and provide installation instructions to improve user experience.

The website preview

Checklist

Essentials

• PR's title starts with a category (e.g. [BUGFIX], [MODEL], [TUTORIAL], [FEATURE], [DOC], etc)
• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage
• Code is well-documented

Changes

• Feature1, tests, (and when applicable, API doc)
• Feature2, tests, (and when applicable, API doc)

Comments

• If this change is a backward incompatible change, why must this change be made.
• Interesting edge cases to note here

[mxnet-bot]

Hey @barry-jin , Thanks for submitting the PR
All tests are already queued to run once. If tests fail, you can trigger one or more tests again with the following commands:

• To trigger all jobs: @mxnet-bot run ci [all]
• To trigger specific jobs: @mxnet-bot run ci [job1, job2]

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CI supported jobs: [website, sanity, edge, centos-gpu, windows-cpu, centos-cpu, unix-gpu, windows-gpu, miscellaneous, unix-cpu, clang]

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Note:
Only following 3 categories can trigger CI :PR Author, MXNet Committer, Jenkins Admin.
All CI tests must pass before the PR can be merged.

[barry-jin]

@mxnet-bot run ci [centos-cpu]

[mxnet-bot]

Jenkins CI successfully triggered : [centos-cpu]