react router: UserDetails modal is already functioning, so this bonus task is already completed

[jsms90]

The path /messages/:username/detail should display the UserDetail of a Conversation. The path /messages/:username should not display the UserDetail of a Conversation. You can navigate to /messages/:username/detail by clicking on the Link component in src/components/Messenger/Conversation/ConversationBar

This feature is already working in the current codebase, so most people just moved on to the next bonus question

In order to make the bonus question something that student's can complete & learn from, we would need to remove this functionality from the initial codebase.