Create generic library generation template for inclusion with APIs

Description

Following from work in uis/devops/iam/activate-account/api#23 (closed), 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

Acceptance criteria

• CI template exists, matching functionality from uis/devops/iam/activate-account/api#23 (closed)
• CI template usage is documented in the guidebook
• Book in a show and tell entry

Links/references