[support.initlist] "initializer list" should be "initializer_list" (#6680)

This note is talking about the class type, not the grammatical construct.

Author: Quuxplusone

source/support.tex

@@ -4139,7 +4139,7 @@
 A pair of pointers or a pointer plus
 a length would be obvious representations for \tcode{initializer_list}.
 \tcode{initializer_list} is used to implement initializer lists as specified
-in~\ref{dcl.init.list}. Copying an initializer list does not copy the underlying
+in~\ref{dcl.init.list}. Copying an \tcode{initializer_list} does not copy the underlying
 elements.
 \end{note}