Fix leaking markdown code cage

Author: Lommelun

Rules.md

@@ -848,6 +848,7 @@ Option | Description
       static let foo = "foo"
       static let bar = "bar"
   }
+```
 
 </details>
 <br/>

Sources/Rules/EnumNamespaces.swift

@@ -65,6 +65,7 @@ public extension FormatRule {
               static let foo = "foo"
               static let bar = "bar"
           }
+        ```
         """
     }
 }