fix all type errors

components/LetterOptions.tsx

@@ -11,7 +11,7 @@ import { IDocProps } from '../interfaces/IDocProps'
 const EXAMPLE_ADDRESS = 'Max Mustermann\nMusterstr. 73\n12345 Musterstadt'
 
 interface IProps extends IDocProps {
-  onChange: () => void
+  onChange: (name: string, event: React.ChangeEvent<{ value: string }>) => void
 }
 
 export default function LetterOptions(props: IProps) {