Update Get-Started-Guide for JIRA67717

[achamuah]

Added the 'Install GPU plugin' section as per https://jira.devtools.intel.com/browse/ITEP-67717.

Pull Request Template

Description

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that are required for this change.

Fixes # (issue)

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[abjyoti]

Is the following Functionality tested? Install GPU plugin - Node Feature Discovery (NFD)