Lift deployment README material into dedicated section
We have a very brief overview of our Google deployments in the guidebook but it misses a number of details.
In addition we have a number of post- and pre-deployment manual bootstrapping steps which are ending up scattered across READMEs. (See, e.g., the README changes in https://gitlab.developers.cam.ac.uk/uis/devops/raven/deploy-raven-core/-/merge_requests/10/)
Update the guidebook with a dedicated section on deployment. Move the existing GCP deployment overview note into the section and add:
- Manual steps required for our deployments including:
- DNS configuration
- Stackdriver workspace creation
- GitLab token creation
- Information on how our webapps get deployed including:
- CI templates
- Deployment from staging to production via the GitLab "environments" tab.
As part of this we may want to expand visibility of the boilerplate deployment from "internal" to "public".