Update ZW-PVO examples to use hyphens instead of slashes

[leilafarsani]

Description

The example identifiers on the ZW-PVO list page currently use / within the identifier.

For example:

• ZW-PVO-42/10
• ZW-PVO-15/2003

These should use a hyphen (-) instead:

• ZW-PVO-42-10
• ZW-PVO-15-2003

Page: https://org-id.guide/list/ZW-PVO

Acceptance criteria

• Replace / with - in the ZW-PVO example identifiers.
• Confirm all examples on the ZW-PVO page follow the correct identifier format.