Add-AgDatabase, shorter Example

[niphlod]

Type of Change

• [ ] Bug fix (non-breaking change, fixes # )
• [ ] New feature (non-breaking change, adds functionality, fixes # )
• [ ] Breaking change (affects multiple commands or functionality, fixes # )
• [ ] Ran manual Pester test and has passed (.\tests\manual.pester.ps1)
• [ ] Adding code coverage to existing functionality
• [ ] Pester test is included
• [ ] If new file reference added for test, has is been added to github.com/dataplat/appveyor-lab ?
• [ ] Unit test is included
• [x] Documentation
• [ ] Build system

Purpose

Shorter example so it doesn't get crippled in the docs page. Fixes https://github.com/dataplat/docs/issues/84

[potatoqualitee]

Grazieeeee 🇮🇹