Fix 404 internal server error

app/__init__.py

@@ -40,7 +40,8 @@ def render_page(page):
 def get_pandoc_page(page):
     path = f'{PANDOC_PATH}/{page}'
     if not os.path.exists(f'{path}'):
-        abort(404)
+        # TODO: Add 404 handler
+        return 'This page does not exist'
     with open(f'{path}/config.json') as f:
         data = json.loads(f.read())
     if not os.path.exists(f'{path}/render.html') or not os.path.exists(f'{path}/render.html.lock'):