(feat) Create ClassList Component

[anthonypecchillo]

This will be a grid view of all of the courses the logged in teacher teaches.

[anthonypecchillo]

• The grid should default to a single row of 3 columns.
• There will be a '+ Show More' link at the bottom right of the grid.
  • Clicking this button should expand the grid to as many rows as needed.

To think about:

• How will we add new classes?