Default settings

src/app.rs

@@ -23,10 +23,10 @@ pub struct Simulation {
 impl Default for Simulation {
     fn default() -> Self {
         Self {            
-            circles_count: 3,
+            circles_count: 4,
             circles: Vec::new(),
             colors: Vec::new(),
-            show_extras: true,
+            show_extras: false,
         }
     }
 }