Apply Hubert's feedback

Co-authored-by: Hubert Tong <[email protected]>

Author: cor3ntin

source/templates.tex

@@ -318,7 +318,7 @@
 called \tcode{T}, rather than an unnamed non-type
 template parameter of class \tcode{T}.
 \end{example}
-A \grammarterm{parameter-declaration} of a \grammarterm{template-parameter}
+The \grammarterm{parameter-declaration} of a \grammarterm{template-parameter}
 shall not have a \grammarterm{storage-class-specifier}.
 Types shall not be defined in a template parameter
 declaration.