AdfsFarm: Add AdminConfiguration Parameter

[X-Guardian]

Pull Request (PR) description

This PR adds the AdminConfiguration parameter to the AdfsFarm resource.

This Pull Request (PR) fixes the following issues

• Fixes #42

Task list

• [x] 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).
• [x] Resource documentation added/updated in README.md.
• [x] Resource parameter descriptions added/updated in README.md, schema.mof and comment-based help.
• [x] Comment-based help added/updated.
• [ ] Localization strings added/updated in all localization files as appropriate.
• [x] Examples appropriately added/updated.
• [x] Unit tests added/updated. See DSC Community Testing Guidelines.
• [ ] Integration tests added/updated (where possible). See DSC Community Testing Guidelines.
• [x] New/changed code adheres to DSC Community Style Guidelines.

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This change is 

[codecov[bot]]

Codecov Report

Merging #43 (4cdd190) into master (02e556d) will increase coverage by 0%. The diff coverage is 100%.

@@          Coverage Diff          @@
##           master    #43   +/-   ##
=====================================
  Coverage      98%    98%           
=====================================
  Files          16     16           
  Lines        2061   2068    +7     
=====================================
+ Hits         2025   2032    +7     
  Misses         36     36