Document Training Booking System

From https://gitlab.developers.cam.ac.uk/uis/devops/admin/-/issues/205 using the template from !53 (merged)

added to epic uis/devops&24 (closed)

added Documentation workflowSprint Ready labels

changed time estimate to 1d

changed milestone to %DevOps Sprint 119

mentioned in merge request !63 (merged)

added workflowReview Required label and removed workflowSprint Ready label

added workflowRework label and removed workflowReview Required label

added 30m of time spent at 2021-04-15

mentioned in commit a166d687

closed with merge request !63 (merged)