refactoring: descriptions to complex functions in operation handler

src/operationHandler.c

@@ -38,6 +38,7 @@ int* evaluateInput(char* input, int operation) {
     return result;
 }
 
+// formatting check of string
 bool containsTwoNumbers(const char* str) {
     int numbersCount = 0;
     bool hasSpace = false;
@@ -62,6 +63,7 @@ bool containsTwoNumbers(const char* str) {
     return (numbersCount == 2 && hasSpace);
 }
 
+// extracting of first number and removing from string
 int extractFirstNumber(char* str) {
     int number = 0;
     bool isInNumber = false;