impl move scheduled to todo when schedule triggers

pttodo/root.go

@@ -5,3 +5,16 @@ type Root struct {
 	Scheduled []Todo
 	Done      []Todo
 }
+
+func (root *Root) MoveScheduledToTodo() {
+	for i := len(root.Scheduled) - 1; i >= 0; i-- {
+		if root.Scheduled[i].Triggered() {
+			root.Todo = append(root.Todo, root.Scheduled[i])
+			root.Scheduled[i] = root.Scheduled[len(root.Scheduled)-1]
+			root.Scheduled = root.Scheduled[:len(root.Scheduled)-1]
+			if i < len(root.Scheduled)-1 {
+				i += 1
+			}
+		}
+	}
+}