docs: Add bst artifact delete to using_commands.rst
diff --git a/doc/source/using_commands.rst b/doc/source/using_commands.rst
index 312b907..53c3619 100644
--- a/doc/source/using_commands.rst
+++ b/doc/source/using_commands.rst
@@ -101,6 +101,13 @@
 .. click:: buildstream._frontend.cli:artifact_push
    :prog: bst artifact push
 
+----
+
+.. _invoking_artifact_delete:
+
+.. click:: buildstream._frontend.cli:artifact_delete
+   :prog: bst artifact delete
+
 
 Source subcommands
 ------------------