feat: sum exercise added

Author: elfroot-sj

exercises/sum.cpp

@@ -1,8 +1,17 @@
-/*
-  Write a program that takes as input two numbers and print the sum.
+/* Reminder -- Gli studenti della Steve Jobs non potranno scrivere in C++
+ quindi scriveremo in linguaggio JavaScript  */
 
-  Output:
-  Insert the first number: 1
-  Insert the second number: 2
-  Sum: 3
-*/
+const readline = require('readline');
+
+const rl = readline.createInterface({
+  input: process.stdin,
+  output: process.stdout
+});
+
+rl.question('Insert the first number: ', (num1) => {
+    rl.question('Insert the second number: ', (num2) => {
+        const result = num1 + num2;
+        console.log("Sum: " + result);
+        rl.close();
+    });
+});