issue-9: finishing keybinding service and implemented controller

Have now got rebinding keys working with the "rebind" command.
Still need to make sure key names are correct and implement rebinding
as part of an RC file and add bindings for the table.

cmd/dynamo-browse/main.go

@@ -98,15 +98,17 @@ func main() {
 		},
 	}
 
-	commandController := commandctrl.NewCommandController()
 	keyBindingService := keybindings.NewService(defaultKeyBindings)
-	_ = keyBindingService
+	keyBindingController := controllers.NewKeyBindingController(keyBindingService)
+
+	commandController := commandctrl.NewCommandController()
 
 	model := ui.NewModel(
 		tableReadController,
 		tableWriteController,
 		itemRendererService,
 		commandController,
+		keyBindingController,
 		defaultKeyBindings,
 	)