[Elementary] Allow course linking to important Info page

[AmyO13]

Problem statement:

When helping with navigation, I cannot use the course link feature to directly link something to the important info page. I can do external link, but then it opens in a new tab which creates clutter and confuses students.

Proposed solution:

Add 'Important Info' as an option for course linking within C4E so that students can have multiple ways to access that information.

User role(s):

admin,instructor