Replace mobx-state-tree with mobx and get a basic home feed rendering

src/view/com/Feed.tsx

@@ -0,0 +1,17 @@
+import React from 'react'
+import {observer} from 'mobx-react-lite'
+import {Text, View} from 'react-native'
+import {FeedViewModel} from '../../state/models/feed-view'
+import {FeedItem} from './FeedItem'
+
+export const Feed = observer(function Feed({feed}: {feed: FeedViewModel}) {
+  return (
+    <View>
+      {feed.isLoading && <Text>Loading...</Text>}
+      {feed.hasError && <Text>{feed.error}</Text>}
+      {feed.hasContent &&
+        feed.feed.map(item => <FeedItem key={item.key} item={item} />)}
+      {feed.isEmpty && <Text>This feed is empty!</Text>}
+    </View>
+  )
+})