Staking strategy with a fair reward distribution.

The Staking event begins with fixed pool size and staking time. How to deal with fairy things?
- (1) The reward should be fixed at staking time and maybe grow up in the future.
- (2) The sooner staking is, the more reward the staker gets.
- (3) The longer staking is, the more reward the staker gets.

https://github.com/nhancv/nideas/blob/main/StakingCoinEvent.pdf