includes link to the repo where the example data is stored

[PippaClarkGDS]

Why

Need to include example data to help users with building mocks

What

Includes link to repo where example data is stored

Technical writer support

This will need tech writer review

How to review

n/a

Changelog

Needs updating on Changelog

Confirm

• [y] I have checked if any docs change here also requires updates to other repositories (ADRs / RFCs, README.md, Team Manual, elsewhere in these docs)
• [y] Where there is any overlap I have updated or opened a PR for corresponding changes