Programs should take an init type/function as the first argument

This is in line with the way Elm works. Also update examples.

examples/views/main.go

@@ -28,7 +28,7 @@ type frameMsg struct{}
 
 func main() {
 	p := tea.NewProgram(
-		Model{0, false, 10, 0, 0, false},
+		initialize,
 		update,
 		view,
 		[]tea.Sub{tick, frame},
@@ -38,6 +38,12 @@ func main() {
 	}
 }
 
+// INIT
+
+func initialize() (tea.Model, tea.Cmd) {
+	return Model{0, false, 10, 0, 0, false}, nil
+}
+
 // SUBSCRIPTIONS
 
 func tick(model tea.Model) tea.Msg {