[Global chat] Part 3: Close chat button for mobile and desktop
That's the part 3 for the UI.
- Bootstrapping Global Chat: https://gitduck.com/watch/5da5e3f7951a393273f21c22
- UI Part 1: https://gitduck.com/watch/5da5f47d951a395269f21c27
- UI Part 2: https://gitduck.com/watch/5da61646951a398436f21c2c
- UI Part 3: https://gitduck.com/watch/5da63419951a390a16f21c30
