In one sentence, describe what the following article is about:

Don't over mix.
In a large bowl, whisk together flour, cornmeal, baking powder, baking soda, salt and brown sugar. In a medium bowl, whisk together the milk, egg and melted butter until the mixture becomes smooth. Pour the buttermilk mixture into the flour mixture and stir it all together until it's just combined. Add the zucchini to the mixture and stir to evenly distribute it. Pour the batter into the prepared pan and spread it out evenly.