Add struct and linked list example on struct obj

tests/test1.c

@@ -0,0 +1,25 @@
+#include "stdio.h"
+#include "stdlib.h"
+
+struct person {
+    char name[20];
+    int age;
+};
+
+struct student {
+    int id;
+    struct person info;
+    struct student *next;
+};
+
+void add_first();
+void add_last();
+void remove_first();
+void remove_last();
+void show();
+void quite();
+
+int main() {
+
+    printf("Goodbye!");
+}