A variety of best fit lines. During development run the following to try it out:
```bash
plotrs -g scatter -c linear.ron -o .
plotrs -g scatter -c quadratic.ron -o .
plotrs -g scatter -c cubic.ron -o .
plotrs -g scatter -c polynomial.ron -o .
plotrs -g scatter -c exponential.ron -o .
plotrs -g scatter -c gaussian.ron -o .
plotrs -g scatter -c sin.ron -o .
plotrs -g scatter -c cos.ron -o .
```