feat: return 404 when ID not in featured threads

threads.py

@@ -19,8 +19,11 @@ def home():
 
 @threads.route('/<path:id>')
 def thread(id):
+    if id in thread_ids:
         status = fetch_thread(id)
         return render_template('threads.html', threads=[status], title=title, attribution=attribution)
+    else:
+        return '<h1>Not Found</h1><p>¯\_(ツ)_/¯</p><a href="/">go home</a>', 404
 
 @threads.route('/api')
 def api():
@@ -30,6 +33,7 @@ def api():
 def api_thread(id):
     return fetch_thread(id)
 
+
 def fetch_statuses():
     statuses = []
     for id in thread_ids: