[landing] add feature cards to competitor comparison

Summary:
This diff is the second part to the introduction of the competitor comparison. This part introduces the feature cards and all the functionality around it including clicking on a card to view the feature modal and changing the cards based on what competitor was selected

Design:

Depends on D8034

Test Plan:
Please watch the demo videos/see the screenshots to see how the competitor comparison looks/behaves with the cards

Desktop/Responsive and General Behavior:

Tablet:

Mobile:

Reviewers: atul, kamil

Reviewed By: atul

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D8038