A small typo in gaussian-process-gaussian-mixture-model

[LiyuanHsu]

@heethesh In gaussian-process-gaussian-mixture-model.md, \( \alpha_k \)is the probability that the observed data is from the \( k \)th gaussian, \( \alpha_k > 0 \), \( \Sigma_{k=1}^{N}\alpha_k=1 \): the summation range for alpha_k should be from 1 to K, I guess.

[heethesh]

Fixed, thanks!