[v1.x] Fix cu100 pip link

[waytrue17]

Description

Fix cu100 pip link

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 @waytrue17 , 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]

---

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

---

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.

[samskalicky]

Can we try and fix the formatting so that the list shows up correctly? It looks ok here:
https://github.com/apache/incubator-mxnet/blob/ea66f6cd6e0f0641aa5054ecc0d31b4a88b3d6d4/tools/pip/doc/CU101_ADDITIONAL.md
but then turns into a jumbled paragraph here: https://pypi.org/project/mxnet-cu101/

Heres the PyPI format info: https://pypi.org/help/#description-content-type

it looks like we set long_description_content_type here:
https://github.com/apache/incubator-mxnet/blob/a192bcac1f02757c452a9cc947ea44bdd86c213b/tools/pip/setup.py#L182

Using https://pypi.org/project/readme-renderer/ it generates this html:

<h2>Prerequisites</h2>
<p>This package supports Linux and Windows platforms. You may also want to check:
- [mxnet-cu110](<a href="https://pypi.python.org/pypi/mxnet-cu110/" rel="nofollow">https://pypi.python.org/\
pypi/mxnet-cu110/</a>) with CUDA-11.0 support.
- [mxnet-cu102](<a href="https://pypi.python.org/pypi/mxnet-cu102/" rel="nofollow">https://pypi.python.org/\
pypi/mxnet-cu102/</a>) with CUDA-10.2 support.
- [mxnet-cu101](<a href="https://pypi.python.org/pypi/mxnet-cu101/" rel="nofollow">https://pypi.python.org/\
pypi/mxnet-cu101/</a>) with CUDA-10.1 support.
- [mxnet-cu92](<a href="https://pypi.python.org/pypi/mxnet-cu92/" rel="nofollow">https://pypi.python.org/py\
pi/mxnet-cu92/</a>) with CUDA-9.2 support.
- [mxnet](<a href="https://pypi.python.org/pypi/mxnet/" rel="nofollow">https://pypi.python.org/pypi/mxnet/<\
/a>).</p>

adding a newline between the sentence and the list seems to work and generates this html:

<h2>Prerequisites</h2>
<p>This package supports Linux and Windows platforms. You may also want to check:</p>
<ul>
<li>[mxnet-cu110](<a href="https://pypi.python.org/pypi/mxnet-cu110/" rel="nofollow">https://pypi.python.or\
g/pypi/mxnet-cu110/</a>) with CUDA-11.0 support.</li>
<li>[mxnet-cu102](<a href="https://pypi.python.org/pypi/mxnet-cu102/" rel="nofollow">https://pypi.python.or\
g/pypi/mxnet-cu102/</a>) with CUDA-10.2 support.</li>
<li>[mxnet-cu101](<a href="https://pypi.python.org/pypi/mxnet-cu101/" rel="nofollow">https://pypi.python.or\
g/pypi/mxnet-cu101/</a>) with CUDA-10.1 support.</li>
<li>[mxnet-cu92](<a href="https://pypi.python.org/pypi/mxnet-cu92/" rel="nofollow">https://pypi.python.org/\
pypi/mxnet-cu92/</a>) with CUDA-9.2 support.</li>
<li>[mxnet](<a href="https://pypi.python.org/pypi/mxnet/" rel="nofollow">https://pypi.python.org/pypi/mxnet\
/</a>).</li>
</ul>

[samskalicky]

Thanks @waytrue17 !