Global (monorepo) build command for documentation with sphinx-collections

[jgarte]

mkdocs-monorepo-plugin mentions in the README the following:

The same great Mkdocs developer experience. It is possible to run mkdocs serve in the root to merge all of your documentation together, or in a subfolder to build specific documentation. Autoreload still works as usual. No more using symlinks!

What would be the sphinx-collections equivalent of running mkdocs serve in the root in order to build and merge together all of your individual documentation projects?