README.MD

Week 4 - Ordinary Differential Equations

From 6.2, error at different step sizes for Euler integration (both are diverging) and Runge-Kutta with much smaller error.

From 6.3, adaptive Runge-Kutta stepper's step size increasing to meet a desired error target. Could have used a more aggressive minimum error term to see the steps oscillate with the derivative instead of just meeting the requirements of the peak derivative.