typo: interation -> iteration

Author: nschonni

docs/standard-library/multiset-class.md

@@ -1841,7 +1841,7 @@ int main() {
       cout << *ms1_Iter << " ";
    cout << "." << endl;
 
-   // rend can be used to terminate an interation
+   // rend can be used to terminate an iteration
    // through a multiset in a reverse order
    cout << "The reversed multiset is: ";
    for ( ms1_rIter = ms1.rbegin( ) ; ms1_rIter != ms1.rend( ); ms1_rIter++ )