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/components/navbar/navigation/MobileBottomBar.tsx

@@ -10,6 +10,7 @@ import { ListItem } from '@mui/material';
 import { styled, Box } from '@mui/system';
 import { Link as RRDLink, useLocation } from 'react-router-dom';
 import { useTheme } from '@mui/material/styles';
+import { NavbarItem } from 'typings';
 
 const BottomNavContainer = styled('div')(({ theme }) => ({
     bottom: 0,