[PIP] update short desc for pip

[szha]

Description

update short desc for pip per branding guidance

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

• update short desc for pip per branding guidance

[mxnet-bot]

Hey @szha , Thanks for submitting the PR
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