Change log for AzureDevOpsDsc

The format is based on and uses the types of changes according to Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

AzureDevOpsDsc
- Updated pipeline files to support change of default branch to main.
- Added GitHub issue templates and pull request template (issue #1)
- Added the AzDevOpsProject, DSC Resource
- Fixed non-terminating, integration tests (issue #18)
- Increased Azure DevOps, API timeout to 5 minutes to allow for busy/slow API operations (issue #25).
- Updated contextual help (issue #5).
- Removed Classes directory from being output in packaged module (issue #10).
- Removed Examples directory from being output in packaged module (issue #11).
- Moved 'Ensure' and 'RequiredAction' enums into 'Enum' directory and out of 'prefix.ps1' (issue #12).
- Added pipeline support for publish markdown content to the GitHub repository wiki (issue #15). This will publish the markdown documentation that is generated bu the build pipeline.
- Added new source folder WikiSource. Every markdown file in the folder WikiSource will be published to the GitHub repository wiki. The markdown file Home.md will be updated with the correct module version on each publish to gallery (including preview).
AzureDevOpsDsc.Common
- Added 'wrapper' functionality around the Azure DevOps REST API

AzureDevOpsDsc
- Enabled integration tests against https://dev.azure.com/azuredevopsdsc/ (see comment #9 (comment) for more information).
- Updated pipeline file RequiredModules.ps1 to latest pipeline pattern.
- Updated pipeline file build.yaml to latest pipeline pattern.
- Updated pipeline file azure-pipelines.yml to use correct images (hosted runners) and correct task for artifacts.
AzDevOpsProject
- Added a validate set to the parameter SourceControlType to (for now) limit the parameter to the values Git and Tfvc.
- Update comment-based help to remove text which the valid values are since that is now add automatically to the documentation (conceptual help and wiki documentation).