Fix dead links for DDA v2alpha1 examples

[khewonc]

What does this PR do?

Fix dead links for example DDAs on https://github.com/DataDog/datadog-operator/blob/main/docs/configuration.v2alpha1.md. The Manifest with Logs and metrics collection enabled example file was removed entirely so I removed that link.

Motivation

https://github.com/DataDog/datadog-operator/issues/1176

Additional Notes

Anything else we should know when reviewing?

Minimum Agent Versions

Are there minimum versions of the Datadog Agent and/or Cluster Agent required?

• Agent: vX.Y.Z
• Cluster Agent: vX.Y.Z

Describe your test plan

Write there any instructions and details you may have to test your PR.

Checklist

• [x] PR has at least one valid label: bug, enhancement, refactoring, documentation, tooling, and/or dependencies
• [x] PR has a milestone or the qa/skip-qa label