Please add DISTRIBUTIONS

[Symbolics]

https://github.com/Lisp-Stat/distributions

The Distributions package provides a collection of probability distributions and related functions including:

• Sampling from distributions
• Moments (e.g mean, variance, skewness, and kurtosis), entropy, and other properties
• Probability density/mass functions (pdf) and their logarithm (logpdf)
• Moment-generating functions and characteristic functions
• Maximum likelihood estimation
• Distribution composition and derived distributions