Update doc for `Uniform`
//! * Mean: $\frac{a + b}{2}$
//! * Var : $\frac{1}{12}(b-a)^2$
//! * To generate uniform random number, Peroxide uses `rand` crate
+//! * **Caution**: `Uniform(T, T)` generates `T` type samples (only for `Uniform`)
//!
//! ```rust
//! extern crate peroxide;
//!
//! fn main() {
//! // Uniform(start, end)
-//! let a = Uniform(0, 1);
+//! let a = Uniform(0f64, 1f64); // It will generate `f64` samples.
//! a.sample(100).print();
//! a.pdf(0.2).print();
//! a.mean().print();
