Add AddItem page base

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

src/screens/addItem.tsx

@@ -0,0 +1,14 @@
+import React from 'react';
+
+import { Text } from 'react-native-paper';
+import { PaddedView } from '../components';
+
+const AddItem = () => {
+  return (
+    <PaddedView centered>
+      <Text>Add Item</Text>
+    </PaddedView>
+  );
+};
+
+export default AddItem;

src/screens/index.ts

@@ -1,3 +1,4 @@
+export { default as AddItem } from './addItem';
 export { default as Home } from './home';
 export { default as Search } from './search';
 export { default as Tags } from './tags';