Refactor app in to its own slice

slices/main/templates/statuses/index.html.slim

@@ -0,0 +1,8 @@
+div class="mb-12 prose dark:prose-invert max-w-prose mx-auto text-gray-800 dark:text-gray-200"
+  h1 Statuses
+
+div class="h-feed mb-12 max-w-prose mx-auto"
+  - posts.each do |post|
+    == render "shared/status", post: post
+
+div class="max-w-screen-md mx-auto border-t border-solid border-gray-200 dark:border-gray-600"