refactoring: added comments describing the function's behavior and use in header file

src/conversionOfNumbers/conversionOfNumbers.h

@@ -1,11 +1,31 @@
 #ifndef CONVERSIONOFNUMBERS_H
 #define CONVERSIONOFNUMBERS_H
 
+// This function converts an integer into a string of according binary digits. If the integer is below zero,
+// a minus sign will be added in front of the string of binary digits.
+// For the sake of simplicity there will be no use of the two's complement.
+// Note: if allocation of memory doesn't work correctly, function will return NULL.
 char* convertIntToBinaryStr(int input);
+
+// This function determines the length of the string needed for the representation of an integer in binary digits.
 int binaryStrLen(int input);
+
+// This function converts a string of binary digits into the according decimal number.
+// For the sake of simplicity it can only convert positive numbers into unsigned integers.
 unsigned int convertBinaryStrToInt(char* input);
+
+// This function converts an integer into an according string representing the integer in the hexadecimal system.
+// Note: Need to check if the input integer is positive as implementation for converting negative integers
+// is not done yet (for the sake of time).
+// Note: if allocation of memory doesn't work correctly, function will return NULL.
 char* convertIntToHex(int input);
+
+// This function determines the length of the string needed for the representation of an integer 
+// in the hexadecimal system.
 int hexStrLen(const int input);
+
+// This function converts a hexadecimal number as a string into the according decimal number.
+// For the sake of simplicity it can only convert positive numbers into unsigned integers. 
 unsigned int convertHexStrToInt(char* input);
 
 #endif