Show the home page concept graph incrementally for new users.

[pramod-io]

After doing some user research, it turns out that some people are intimidated by the number of terms they need to learn when starting a course.

Automatic Scrolling from the top of the page to the quiz section before the pretest is janky. Also scrolling does not give enough time for the user to read the names of all concepts and their dependencies.

So construct the concept graph incrementally for new users.