added function to get user input

src/fakultaet/main.c

@@ -3,7 +3,10 @@
 #include <stdio.h>
 
 int main() {
+	int minInput = 0;
 
+	printf("Enter a number to calculate its factorial: \n");
+	int number = usergetd("Enter an even number: "), minInput, NULL);
 
 	return 0;
 }