Interactive tutorial

[LightFelicis]

How to use Szkopuł, how to submit problem solution etc. How to use problemset, how to use teacher account.

At least some user quickstart would be nice to have. I suggest creating wiki for users and a pop-up on sio for new accounts linking to the wiki.

[twalen]

Those libraries might be useful:

• https://github.com/shipshapecode/shepherd
• https://github.com/usablica/intro.js (double check license)
• https://bootstraptour.com/