Added info about playbooks for collection (#75535)

*

docs/docsite/rst/dev_guide/developing_collections_structure.rst

@@ -175,7 +175,11 @@ You can migrate 'traditional roles' into a collection but they must follow the r
 playbooks directory
 --------------------
 
-TBD.
+In prior releases, you could reference playbooks in this directory using the full path to the playbook file from the command line.
+In ansible-core 2.11 and later, you can use the FQCN, ``namespace.collection.playbook`` (with or without extension), to reference the playbooks from the command line or from ``import_playbook``.
+This will keep the playbook in 'collection context', as if you had added ``collections: [ namespace.collection ]`` to it.
+
+You can have most of the subdirectories you would expect, such ``files/``, ``vars/`` or  ``templates/`` but no ``roles/`` since those are handled already in the collection.
 
 .. _developing_collections_tests_directory: