Implement walkthrough after the registration
Ref #458 (closed)
Missing parts:
- Visual does not match design from https://www.figma.com/proto/3St14olkpBe07W5hwEZd5Y/Lightmeter?node-id=153%3A1041&scaling=min-zoom&page-id=120%3A0
Early stage implementation. https://www.youtube.com/watch?v=cnE5MdzuBCI
Final version, with improved style for desktop and mobile: https://www.youtube.com/watch?v=pktcBjcpcxo
Edited by Leandro Santiago