Minimap is added

To improve the playability of this game, a minimap is added at the top right of the screen.

More cameras and a plane is added to ensure that the minimap can work.

The gif below shows when the ball moves, it can also be seen in the minimap, which enables the player to know where he/she is and where he/she want to go.

This minimap is made according to the tutorial on this website below:

Reference:

https://blog.csdn.net/dingxiaowei2013/article/details/18260921