fix a box

docs/pages/bash/bash-3-navigating.md

@@ -75,7 +75,8 @@ ls -F -a
 ```
 
 !!! question "What special directory do you observe?"
-    ??? example "Click to show the solution"
+    
+??? example "Click to show the solution"
     We can see a `.` directory as well as a `..` directory.
 
 `.` means the **current working directory**