docs(check_user_name): dont include chec_user_name as associated as per the review

subjects/check_user_name/README.md

@@ -16,6 +16,7 @@ You will also have to create a `User` struct which has:
 - Associated functions:
   - `new`: which initializes the struct.
   - `send_name`: which takes only `self` as argument and returns an `Option<&str>` with `None` if the user is a guest or the `name` if the `AccessLevel` has any of the other options.
+- Other functions:
   - `check_user_name`: which takes a `User`, calls `send_name` and returns a `tuple` with `true` and the user `name` if `send_name` returns the name or `false` and `"Error: User is guest"` if not
 
 ### Expected Functions and Data Structures