remove manually created typing d ts file (#249)

* Rename file

".d.ts" files are files that are automatically generated during compilation (in case option is set) and shouldn't be created manually.

* Export types and interfaces

* Add missing imports

src/screens/settings/DefaultReaderSettings.tsx

@@ -20,6 +20,7 @@ import {
     useDefaultReaderSettings,
 } from 'util/readerSettings';
 import ReaderSettingsOptions from 'components/reader/ReaderSettingsOptions';
+import { IReaderSettings } from 'typings';
 
 export default function DefaultReaderSettings() {
     const { setTitle, setAction } = useContext(NavbarContext);