backstage/.changeset/modern-trees-add.md

@backstage/plugin-techdocs, @backstage/plugin-catalog

@backstage/plugin-techdocs	@backstage/plugin-catalog
minor	minor

This change allows a new annotation of backstage.io/techdocs-entity this ref allows you to reference another entity for its TechDocs. This allows you have a single TechDoc for all items in a system, for example you might have a frontend and a backend in the same repo. This would allow you to have TechDocs build under a System entity while referencing the system e.g.: backstage.io/techdocs-entity: system:default/example that will show the systems docs in both the TechDocs button and the TechDocs tab without needing to do duplicate builds and filling the TechDocs page with garbage.