Moved large parts of the ReadMe to the Wiki

[DennisL68]

Pull Request

Pull Request (PR) description

The README.md was getting pretty big so I'd like to move a large part of it to the Wiki instead

Added

• Gettings-started.md in the Wiki folder [closes #487]

Changed

• Getting started video updated [closes #487]

Deprecated

Security

Fixed

Removed

Task list

• [ ] The PR represents a single logical change. i.e. Cosmetic updates should go in different PRs.
• [x] Added an entry under the Unreleased section of in the CHANGELOG.md as per format.
• [ ] Local clean build passes without issue or fail tests (build.ps1 -ResolveDependency).
• [x] Documentation added/updated in README.md.
• [x] Documentation added/updated in the Wiki.
• [ ] Comment-based help added/updated.
• [ ] Localization strings added/updated in all localization files as appropriate.
• [ ] 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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