Add itch.io JDungeon links to github and jdungeon.org for better navigation.

[WithinAmnesia]

https://jonathaneeckhout.itch.io/jdungeon itch.io link it should be added here:

• https://github.com/jonathaneeckhout/jdungeon (Beside jdungeon.org)
• https://jdungeon.org/ (Above the play now where its 1 click away when website load to be the main way to play the game. As in play game first above then download / learn more / github links below.)