maj du compte rendu et ajout de l'exercice 3

exo3_debug.ts

+function deb2(x: number, y:number): void {
+    const tmp = y;
+    y = x;
+    x = tmp;
+    console.log(x, y);
+}
+
+let x = 10;
+let y = 20;
+deb2(x, y);
+console.log(x, y);
\ No newline at end of file