Fix docs cli example to give the promised run details table output

[bobbyo]

Description

Existing docs give wrong command line at this url; user expects to get tabular output, but command shown gives json output: https://microsoft.github.io/promptflow/how-to-guides/manage-runs.html#show-run-metrics

ISSUE: #2299

The

TEST PLAN:
updated md file renders in vscode, copy & paste of corrected command line works when a real run name is used.

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