Update cpp/cert/src/rules/CTR55-CPP/DoNotUseAnAdditiveOperatorOnAnIterator.ql

Co-authored-by: Remco Vermeulen <rvermeulen@users.noreply.github.com>

Author: knewbury01

cpp/cert/src/rules/CTR55-CPP/DoNotUseAnAdditiveOperatorOnAnIterator.ql

@@ -17,8 +17,9 @@ import codingstandards.cpp.Iterators
 import semmle.code.cpp.controlflow.Dominance
 
 /**
- * something like:
- * `end = begin() + size()`
+ *  Get a derived one passed the end element for `containerReference`.
+ *  An example derivation is:
+ *     `end = begin() + size()`
  */
 Expr calculatedEndCheck(AdditiveOperatorFunctionCall calc) {
   exists(