fix for :fetch_initial_posts

A warning was added, but their were some newlines and whitespaces missing which broke the rendering of the setting. I've added them now

docs/configuration/cheatsheet.md

@@ -152,8 +152,10 @@ config :pleroma, :mrf_user_allowlist,
 * `authorized_fetch_mode`: Require HTTP signatures for AP fetches
 
 ### :fetch_initial_posts
+
 !!! warning
-   Be careful with this setting, fetching posts may lead to new users being discovered whose posts will then also be fetched. This can lead to serious load on your instance and database.
+    Be careful with this setting, fetching posts may lead to new users being discovered whose posts will then also be fetched. This can lead to serious load on your instance and database.
+
 * `enabled`: If enabled, when a new user is discovered by your instance, fetch some of their latest posts.
 * `pages`: The amount of pages to fetch