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/Categories.tsx

@@ -33,6 +33,7 @@ import Checkbox from '@mui/material/Checkbox';
 import FormControlLabel from '@mui/material/FormControlLabel';
 import NavbarContext from 'components/context/NavbarContext';
 import client, { useQuery } from 'util/client';
+import { ICategory } from 'typings';
 
 const getItemStyle = (
     isDragging: boolean,