フッターメニュー
参考にしたサイト
- https://medium.com/@KarthikPonnam/flutter-pageview-withbottomnavigationbar-fb4c87580f6a
- https://www.virment.com/how-to-put-bottom-nav-flutter/
- https://qiita.com/takattata/items/5fa560a95d19623d26fe
- https://github.com/fablue/building-a-social-network-with-flutter
- https://dev.classmethod.jp/articles/basic_bottom_navigation_flutter/