saveload system

localstorage isn't supported by wasm, so playing online will probably just not have save games for a while

src/player.rs

@@ -98,7 +98,7 @@ pub fn player_input(gs: &mut State, ctx: &mut Rltk) -> RunState {
             VirtualKeyCode::G => get_item(&mut gs.ecs),
             VirtualKeyCode::I => return RunState::ShowInventory,
             VirtualKeyCode::D => return RunState::ShowDropItem,
-            VirtualKeyCode::Escape => return RunState::MainMenu { menu_selection: gui::MainMenuSelection::NewGame },
+            VirtualKeyCode::Escape => return RunState::SaveGame,
             _ => {
                 return RunState::AwaitingInput;
             }