Issue #12602: Add missing cross-references to runpy and using/cmdline docs.

Patch by Éric Araujo.
diff --git a/Doc/tutorial/interpreter.rst b/Doc/tutorial/interpreter.rst
index 514c5f1..19094f3 100644
--- a/Doc/tutorial/interpreter.rst
+++ b/Doc/tutorial/interpreter.rst
@@ -62,6 +62,8 @@
 and enter interactive mode afterwards.  This can be done by passing :option:`-i`
 before the script.
 
+All command-line options are described in :ref:`using-on-general`.
+
 
 .. _tut-argpassing: