Remove styles part

At request of @matteobruni

Author: GameLord2011

README.md

@@ -398,17 +398,6 @@ const App = () => {
 };
 ```
 
-### Styles
-
-Add these styles to your global stylesheet.
-
-```CSS
-#tsparticles {
-  z-index: -10;
-  position: relative;
-}
-```
-
 ### Props
 
 | Prop      | Type   | Definition                                           |