Remove incorrectly placed comment

I'm not sure if it should be there at all, but at least it should hardly be where it currently is located.

Signed-off-by: Per Persson <[email protected]>

docs/compose-file.md

@@ -48,8 +48,6 @@ See `man 7 capabilities` for a full list.
       - NET_ADMIN
       - SYS_ADMIN
 
-Using `dockerfile` together with `image` is not allowed. Attempting to do so results in an error.
-
 ### command
 
 Override the default command.
@@ -106,6 +104,8 @@ Compose will use an alternate file to build with.
 
     dockerfile: Dockerfile-alternate
 
+Using `dockerfile` together with `image` is not allowed. Attempting to do so results in an error.
+
 ### env_file
 
 Add environment variables from a file. Can be a single value or a list.