feat: better plot example

README.md

@@ -11,7 +11,7 @@ Example:
 ```
 from plotter.matplotlib import plot_expression
 
-plot_expression("sin(x) * 2^(3*x)", start=-10.0, stop=10.0, increment=0.1)
+plot_expression("abs(sin(x)) + (5 * exp(-100*x^2) * cos(x))", start=-7, stop=7, increment=0.001)
 ```
 
-![Function plotted in the [-10.0, 10.0] range with 0.1 increments](./plot_example.png)
+![Function plotted in the [-7.0, 7.0] range with 0.001 increments](./plot_example.png)