Examples needed

[schnuerle]

All of the APIs and endpoints need examples to be added to the spec to help understand scenarios and usage.

See MDS for ideas:

• https://github.com/openmobilityfoundation/mobility-data-specification/tree/main/policy/examples#policy-examples
• https://github.com/openmobilityfoundation/mobility-data-specification/tree/main/geography/examples#geography-examples
• https://github.com/openmobilityfoundation/mobility-data-specification/tree/main/metrics/examples#metrics-examples
• https://github.com/openmobilityfoundation/mobility-data-specification/tree/main/provider#reports---example