[stmt.expand] Add missing \grammarterm

Author: tkoeppe

source/statements.tex

@@ -914,7 +914,8 @@
   @$S_{N-1}$@
 }
 \end{codeblock}
-where $N$ is the structured binding size of the type of the expansion-initializer and $S_{i}$ is
+where $N$ is the structured binding size of the type
+of the \grammarterm{expansion-initializer} and $S_{i}$ is
 \begin{codeblock}
 {
   @\grammarterm{for-range-declaration}@ = @$u_{i}$@;