Applied final patch, a reminder to add a table.

docs/external_C_code.rst

@@ -159,6 +159,8 @@ header file, and the corresponding Cython declaration that you should put in
 the ``cdef extern`` from block. Struct declarations are used as an example; the
 same applies equally to union and enum declarations.
 
+-- TODO: put table here...
+
 Note that in all the cases below, you refer to the type in Cython code simply
 as :ctype:`Foo`, not ``struct Foo``.