Create generic library generation template for inclusion with APIs
## Description
Following from work in https://gitlab.developers.cam.ac.uk/uis/devops/iam/activate-account/api/-/issues/23, we should move the written template for releasing client library jobs into a generic CI template for other repositories to make use of.
## Further details
This job does not build the schema, it should accept a schema file either as a build artefact from an upstream job or from a location within the repository that is running the job.
## Task list
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## Acceptance criteria
- [x] CI template exists, matching functionality from https://gitlab.developers.cam.ac.uk/uis/devops/iam/activate-account/api/-/issues/23
- [x] CI template usage is documented in the guidebook
- [x] Book in a show and tell entry
## Links/references
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