refactor(theming): split up styles

src/additional-components/index.ts

@@ -1,5 +1,5 @@
 // These components are not used by React Flow directly
-// but the user can add them as a child of a React Flow component
+// but the user can add them as children of a React Flow component
 
 export { default as MiniMap } from './MiniMap';
 export { default as Controls } from './Controls';