Fix QLDoc article in NumericLiteral comment

Author: Copilot

cpp/common/src/codingstandards/cpp/Cpp14Literal.qll

@@ -7,7 +7,7 @@ module Cpp14Literal {
   private import cpp as StandardLibrary
   private import codingstandards.cpp.UserDefinedLiteral
 
-  /** An numeric literal. */
+  /** A numeric literal. */
   abstract class NumericLiteral extends StandardLibrary::Literal {
     NumericLiteral() {
       // exclude user-defined literals as they define custom suffixes