Pipeline instructions

[pmatthews05]

85

PR Checklist

---

• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• My code follows the code style of this project.
• I ran lint checks locally prior to submission.
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Description

Created a step by step instruction on deploying pipeline using sandpit. Ensuring a person following along would not require to much previous knowledge of how the project hangs together.

Update to paths in pipelines to ensure it would work.

Does this introduce a breaking change

• YES
• NO

Testing

Follow the instructions inside configuration/sandpit/pipelines/README-pipelines.md from beginning to end in a clean environment.

[ghost]

All CLA requirements met.

[arnaudlh]

thanks @pmatthews05 for your contribution to CAF Terraform landing zones, sorry it took a bit of time to get in!