refactoring: change variable names and format code in calculatorSubtract.c and calculatorSubtract.h

src/calculatorSubtract.c

@@ -1,5 +1,12 @@
 #include "calculatorSubtract.h"
 
-float calculatorSubtract(float x, float y){return x-y;}
+// Note:
+/* This Function may or may not be implemented in actual program, even if it is merged to the main branch.
+   If it is temporarily not included in the main Program, then this has a role in future Development of the Project */
+
+float calculatorSubtract (float num1, float num2)
+{
+    return num1 - num2;
+}
 
 

src/calculatorSubtract.h

@@ -4,7 +4,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-float calculatorSubtract(float x, float y);
+float calculatorSubtract(float num1, float num2);