Merged joinGame-form to development

.env

src/App.css

src/components/EditGameForm.js

src/components/GameList.js

src/components/GameSidebar.js

src/components/Header.js

src/components/JoinGameForm.js

src/components/LoginForm.js

src/components/NewGameForm.js

src/components/RegisterForm.js

src/components/TaskItem.js