Implement Concept Cards' back description
Feature Description
Have the "more" in the text description display the back of the card with the full description
Like in this picture but with 'concept' instead of 'assessment':
Motivation and Context
Brought up when implementing explanation texts for assessments in #371 (closed)
Possible Implementation
Like in https://gitlab.com/fathom/app/merge_requests/316, have the conceptCard have a local 'displayBackView' state and a local function to toggle it and display full description instead
Related Issues/Tasks
Related and similar to #371 (closed)