Add a short high-level explanation of typical docker-compose use cases

[VNel]

This pull request adds a short, high-level documentation section explaining typical use cases for docker-compose.

While docker-compose is widely used, the documentation currently focuses very quickly on configuration details without clearly outlining when docker-compose is a good fit and when other tools may be more appropriate.

The added section provides a concise overview of common scenarios such as local development, testing, and small setups, and briefly contrasts these with use cases where plain Docker commands or Kubernetes might be better suited.

This change is documentation-only and does not introduce any new features or configuration changes.

Definition of Done (DoD):

• A new high-level section explaining typical docker-compose use cases exists
• The content remains conceptual and concise
• No new features or configuration options are introduced
• Existing documentation structure remains intact
• Documentation renders correctly

Related issue: #13476