added functions to get the two numbers by the user

src/ggT/main.c

@@ -1,5 +1,11 @@
-int main(){
+#include "ggT.h"
+#include "../userinput.h"
+#include <stdio.h>
 
+int main(){
+    printf("add two numbers:\n");
+    int firstNum = usergetd("first number: ", 0, NULL);
+    int secondNum = usergetd("second number: ", 0, NULL);
 
     return 0;
 }