FEATURE: Create a demo page for logged out visitors

[yuanchenmeng]

User Story

• As a visitor
• I can view sample play interfaces
• As a frontend developer
• I can only focus on UI design without the need to be concerned about security and backend.

Overview

This issue creates a demo page located at/demo/play. This demo page only displays static texts so that the frontend developer can focus on UI design only.

This issue prepares for pagination feature for profit table and better modern UI design.

Affiliation

This issue is affiliated to issue #6

Acceptance Criteria

• [x] minor displaying error of components in user home page should be fixed
• [x] Demo page is secure and displays content as expected