docs: fix angle unit in quick start example (#1837)

[CyberneticX-Tech]

Summary

Fixes the unit mentioned in the quick start documentation example in src/lib.rs.

Motivation

Resolves #1837. The ranged sampling example samples a value from -PI..PI. A range of [-π, π] corresponds to radians rather than degrees, so printing "degrees" was misleading for readers running or copying the example.

Details

Updated src/lib.rs:

// Ranged sampling:
use std::f32::consts::PI;
println!("Angle: {} radians", rand::random_range(-PI..PI));

Tested with cargo test --doc and cargo clippy --all-targets (all clean).