title: Add to Cart Function Location
body: <p>I´m totally new to Woocommerce and Wordpress in general. 
  I understand the principle of Hooks and Action, but I don´t know where they are defined. </p>
  
  <p>My plan is to change the action that happens when Add to Cart is pressed, but I don´t know where the code for that is located and can´t find it. </p>
  
  <p>I don´t know if it matters but I´m using the Theme Flatsome. </p>