push all exercices

ch4/3/ch4_3.go

@@ -0,0 +1,12 @@
+package main
+
+import "fmt"
+
+func main() {
+	var total int
+	for i := 0; i < 10; i++ {
+		total = total + i
+		fmt.Println(total)
+	}
+	fmt.Println(total)
+}

ch4/3/go.mod

@@ -0,0 +1,3 @@
+module ch4_3
+
+go 1.25.0