Link to the document for each game.

[0xshora]

Currently, players can not understand the rules for each game.

So, we need UI for a player to recognize each game.

Implementation Idea:

• we can add a ? icon to jump to the document. e.g.: https://pixelaw.github.io/book/games/paint.html
• Or, if a player clicks by the right button, a player can see the link to the document.