message: parameter documentation
diff: // http://opensource.org/licenses/MIT>, at your option. This file may not be
  // copied, modified, or distributed except according to those terms.
  -//! TODO DOCUMENTATION
  +//! # `ArgminParameter`
  //!
  +//! This module provides the `ArgminParameter` trait which every parameter vector fed into an
  +//! solver must implement.
  +//!
  +//! This trait is so far implemented for:
  +//! * `Vec<f64>`
  +//! * `Vec<f32>`
  +//! * `ndarray::Array1<f64>`
  +//! * `ndarray::Array1<f32>`
  use std::fmt::Debug;
  use std::cmp::PartialOrd;
  