Give students the option to highlight a topic so they know where they left the course

It'd work as a normal highlight but the student chooses it. 

If the teacher has already chosen one, I see two options:

• the student shouldn't be able to do it
• then there are two highlights (different colours for example). If that's the case, the Moodle App needs to be considered (right now the app shows first the highlighted topic chose by the teacher, or 'All sections')