Show help for non-enrolled/non-logged-in users how to submit tasks

[messa]

For better UX :)

When student is logged in and enrolled in the course (has the student role), she/he sees a submit form.

But otherwise, there is no submit form and even no info how to get to the submit form (log in, add herself to the course...) So what if we put some help text there (in the exact place where the first submit form on the page would be)?