Remove class Ref

Author: cpplearner

source/ranges.tex

@@ -2270,7 +2270,7 @@
 \pnum
 Let \exposid{container-append} be defined as follows:
 \begin{codeblock}
-template<class Ref, class Container>
+template<class Container>
 constexpr auto @\exposid{container-append}@(Container& c) {                    // \expos
   return [&c]<class Ref>(Ref&& ref) {
     if constexpr (requires { c.emplace_back(declval<Ref>()); })