[Feature Request] Documentation of Nelder-Mead method

**Problem**

When Nelder-Mead method is applied to a simple quadratic polynomial, the minimization is unable to identify the minimum. It is quite close, but the modification of `StopCriterion` or the `NmConfig` isn't trivial without further documentation.

**Solution**

Description of the fields in the documentation.

**Steps to reproduce**

```fsharp
#r "nuget: Plotly.NET"
#r "nuget: FSharp.Stats, 0.4.12-preview.2"

open FSharp.Stats
open FSharp.Stats.Optimization
open System

open Plotly.NET

let myFunction (xs: vector) =
let x = xs.[0]
x**2. - 0.32*x - 0.13

// initial guess for the optimization
let x0 = vector [| -0.3 |]

// default solver options
let nmc = NelderMead.NmConfig.defaultInit()

// optimization procedure
let optim =
//let stopCrit =
// { OptimizationStop.defaultStopCriteria with MinFunctionEpsilon = 1e-24 }
//NelderMead.minimizeWithStopCriteria nmc x0 myFunction stopCrit
NelderMead.minimize nmc x0 myFunction

(*
optim.Vectors just contains 3 valid vectors
*)

let validVectors = 3

// optimization results as x, y, and z coordinate
let xs,ys =
optim.Vectors.[0..validVectors - 1] |> Array.map (fun x -> x.[0],myFunction x)
|> Array.unzip

let optimizationPathchart =
[
[-1. .. 0.005 .. 1.] |> List.map (fun x -> x,myFunction (vector [x])) |> Chart.Line
Chart.Line(x=xs,y=ys,ShowMarkers=true,Name="Optimization path")
Chart.Point([optim.SolutionVector.[0],optim.Solution],Name="Solution")
]
|> Chart.combine
|> Chart.withTemplate ChartTemplates.lightMirrored
|> Chart.withXAxisStyle ("x",ShowGrid=false)
|> Chart.withYAxisStyle ("myFunction(x)",ShowGrid=false)
|> Chart.withSize (800.,800.)

Chart.show optimizationPathchart
```