- set up placeholder and trigger for Deploy Docs workflow in docs-build branch
- set up placeholder and trigger for Rebuild Search Index workflow in docs-build branch
- remove obsolete Deploy Reference workflow
- upgrade Antora to 3.1
- reconfigure docs build for local build only
- add patch to support using linked worktree as Antora content source
- remove Antora extensions only needed for the production docs build
This makes it so that the URL contains security in the root of the deploy
folder. We will do this until we decide to add projects other than the
security related projects.