xActiveDirectory: Add Missing Resource Examples

[X-Guardian]

Pull Request (PR) description

This PR adds examples for the following resources that were missing:

• xADReplicationSubnet
• xADServicePrincipalName
• xWaitForADDomain

It also adds links to these on the example README.md as well as xADObjectEnabledState which was missing from a previous update.

This Pull Request (PR) fixes the following issues

• Fixes xActiveDirectory: Some Resources are missing examples #395

Task list

• Added an entry under the Unreleased section in the CHANGELOG.md.
  Entry should say what was changed, and how that affects users (if applicable).
• Resource documentation added/updated in resource directory README.md.
• Resource parameter descriptions added/updated in schema.mof
  and comment-based help.
• 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 Resource Testing Guidelines.
• Integration tests added/updated (where possible). See DSC Resource Testing Guidelines.
• New/changed code adheres to DSC Resource Style Guidelines and Best Practices.

---

This change is 

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (dev@7fb5aa7). Click here to learn what that means.
The diff coverage is n/a.

@@         Coverage Diff          @@
##             dev   #397   +/-   ##
====================================
  Coverage       ?    92%           
====================================
  Files          ?     20           
  Lines          ?   2538           
  Branches       ?     10           
====================================
  Hits           ?   2345           
  Misses         ?    183           
  Partials       ?     10

[johlju]

Reviewed 5 of 5 files at r1, 1 of 1 files at r3.
Reviewable status: complete! all files reviewed, all discussions resolved

[X-Guardian]

Cheers @johlju. Don't forget to update the Wiki.

(Now if only there was a way that we could do this automatically... 😉)

[johlju]

There is a release coming any day now so I wait until then. :)