ShowParameterHelp: Remove the unnecessary "DESC: " prefix from the parameter description

[mklement0]

Prerequisites

• [X] Write a descriptive title.

Description of the new feature/enhancement

When you invoke the ShowParameterHelp function (bound to Alt+h by default), the parameter description that prints is prefixed with DESC: (e.g., type Get-Item -Path and press Alt+h)

This prefix adds no useful information; I suggest removing it.

Proposed technical implementation details (optional)

No response