add point + doc -> readme

src/main.rs

@@ -58,6 +58,7 @@ enum Message {
     SetMusicLength,
     LengthChange(String),
     ChangeDelta(f32),
+    AddPoint,
 }
 
 struct MyApp {
@@ -171,6 +172,9 @@ impl MyApp {
                     self.update(Message::TogglePaused);
                 }
             }
+            Message::AddPoint => {
+                self.music.add_Point(self.current_delta);
+            }
         }
     }
 
@@ -312,7 +316,8 @@ impl MyApp {
                         delta_to_string(self.current_delta),
                         delta_to_string(self.music.length)
                     ))
-                    .size(20.0)
+                    .size(20.0),
+                    button("Add Point").on_press(Message::AddPoint)
                 ]
                 .spacing(20),
                 column![