Move unresolved ATC question to proper section

Author: cramertj

text/0000-variadic-generics.md

@@ -66,10 +66,6 @@ trait Tuple {
 }
 ```
 
-TODO: should the above use `TupleRef<'a>` and `TupleMut<'b>` traits to avoid
-dependency on ATCs? It seems nicer to have them all together in one trait, but
-it's probably not worth the resulting feature-stacking mess.
-
 The types `AsRefs` and `AsMuts` are the corresponding tuples of references to
 each element in the original tuple. For example,
 `(A, B, C)::AsRefs = (&A, &B, &C)` and
@@ -199,10 +195,15 @@ unified `Tuple`.
 
 # Unresolved questions
 [unresolved]: #unresolved-questions
-It might be useful in the future to expand on the locations where `...Type`
+-It might be useful in the future to expand on the locations where `...Type`
 can be used. Potential extensions to this RFC could allow `...Type` in
 non-tuple generics or in function argument types, like
 `fn foo<Args>(args: ...Args)`.
 This would allow functions and traits to use variadic generics without
 explicit tuples. This could enable things like the proposed `foo[i, j]` syntax
 using`Index<usize, usize>`.
+-Should the `Tuple` trait use separate `TupleRef<'a>` and `TupleMut<'b>` traits
+to avoid dependency on ATCs? It seems nicer to have them all together in one
+trait, but it might not be worth the resulting feature-stacking mess.
+
+