Update task Generate_Markdown_For_DSC_Resources to use old config key

[johlju]

Pull Request (PR) description

• Task Generate_Markdown_For_DSC_Resources
  • Outputs a warning message if the old configuration key is used in the
    build configuration but keeps using the old configuration key.

This Pull Request (PR) fixes the following issues

• Fixes Generate_Markdown_For_DSC_Resources: Cannot find the metadata configuration #161

Task list

• Added an entry to the change log under the Unreleased section of the file CHANGELOG.md.
  Entry should say what was changed and how that affects users (if applicable), and
  reference the issue being resolved (if applicable).
• Documentation added/updated in README.md.
• Comment-based help added/updated.
• Localization strings added/updated in all localization files as appropriate.
• Examples appropriately added/updated.
• Unit tests added/updated. See DSC Community Testing Guidelines.
• Integration tests added/updated (where possible). See DSC Community Testing Guidelines.
• New/changed code adheres to DSC Community Style Guidelines.

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This change is 

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94%. Comparing base (66b21b9) to head (a403f5f).
Report is 3 commits behind head on main.

Additional details and impacted files

@@         Coverage Diff         @@
##           main   #162   +/-   ##
===================================
  Coverage    94%    94%           
===================================
  Files        70     70           
  Lines      1321   1324    +3     
===================================
+ Hits       1244   1247    +3     
  Misses       77     77           

Files with missing lines	Coverage Δ
...asks/Generate_Markdown_For_DSC_Resources.build.ps1	88% <100%> (+2%)	⬆️

[johlju]

Reviewed 2 of 3 files at r1, 1 of 1 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @johlju)