Improve description for test specification

### What

Make clear that you can write a test specification without an implementation to already create traceability. This test must not be executed as there is no implementation behind it. An implementation can follow later. This is specifically useful for fully_verfies test cases.

With fully_verfies test cases you can avoid to set the test covered attribute.

Trigger is the testing community meeting July 1st 2026 and the process meetings from that time.

### Acceptance Criteria (DoD)

Improved process description.

### How

_No response_