Whole new numerical computations

[Axect]

There will be huge update in 0.31.0 - Algebraic Syntax Tree based Automatic Differentiation.
Therefore, there will be significant changes in the numerical calculation API accordingly.

1. Optimize (numeric/optimize.rs)
   • API Change
   • Documentation
   1. Zeroth order (Not relate to AD)
      • Bracket minimum
      • Shubert-Piyavskii
      • Fibonacci
      • Golden Section
      • Quadratic Fit
   2. First Order (Use ADScalarFn)
      • Bisection
      • Gradient Descent
      • Conjugate Gradient
      • Momentum
      • Nesterov Momentum
      • Adagrad
      • RMSprop
      • Adadelta
      • Adam
      • Hypergradient
2. Regression (numeric/reg.rs)
   • API Change
   • Documentation
   1. Linear Regression
      • Ordinary Least Square
      • Ridge
      • LASSO
      • Principal Component Regression
   2. Nonlinear Regression
      • Gradient Descent
      • Gauss-Newton
      • Levenberg-Marquardt
3. Root Finding (numeric/root.rs)
   • API Change
   • Documentation
   1. Bracketing
      • Bisection
      • False Position
      • Secant
   2. First Order
      • Newton-Raphson