Fix multiple top-level headings error.

doc/user/project/push_options.md

@@ -112,6 +112,6 @@ pipeline succeeds:
 git mwps origin <local-branch-name>
 ```
 
-# Server-side Push Rules
+## Server-side Push Rules
 
 For server-side options, See also [Push Rules](https://docs.gitlab.com/ee/push_rules/push_rules.html) for further control and enforcement options.