[atomics.types.generic] Added reference to [atomics.types.operations] in synopsis

Author: Dawn Perchik

source/atomics.tex

@@ -1542,6 +1542,7 @@
     bool is_lock_free() const volatile noexcept;
     bool is_lock_free() const noexcept;
 
+    // \ref{atomics.types.operations}, operations on atomic types
     constexpr atomic() noexcept(is_nothrow_default_constructible_v<T>);
     constexpr atomic(T) noexcept;
     atomic(const atomic&) = delete;