(GH-156) Clarifiy glossary for DSCv3/PSDSC

[michaeltlombardi]

PR Summary

This change further clarifies the distinction and terminology to reduce confusion about PowerShell Desired State Configuration in DSCv3.

PR Checklist

• [x] Descriptive Title: This PR's title is a synopsis of the changes it proposes.
• [x] Summary: This PR's summary describes the scope and intent of the change.
• [x] Contributor's Guide: I have read the contributors guide.
• [x] Style: This PR adheres to the style guide.

[learn-build-service-prod[bot]]

Learn Build status updates of commit 4c29e17:

:white_check_mark: Validation status: passed

File	Status	Preview URL	Details
.vscode/cspell/dsc/dictionaries/dsc-terms.txt	:white_check_mark:Succeeded
.vscode/styles/Vocab/PowerShell-Docs/accept.txt	:white_check_mark:Succeeded
dsc/docs-conceptual/dsc-3.0/concepts/resources.md	:white_check_mark:Succeeded	View (dsc-3.0)
dsc/docs-conceptual/dsc-3.0/glossary.md	:white_check_mark:Succeeded	View (dsc-3.0)
dsc/docs-conceptual/dsc-3.0/overview.md	:white_check_mark:Succeeded	View (dsc-3.0)

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel