[2 points] Make a plot with the raw data points, use `geom_smooth()` to add the line of best fit from the simple linear regression model (containing `medv` and `dis`), and use `geom_abline()` to add a horizontal line with a slope of 0 that crosses the y-axis at the average value of `medv` to vertically bisect the data points. Store your plot as the object `p5`