Use application feature flags in FAQ

[chamkank]

Currently if we turn off an application feature flag (hacker, mentor, or volunteer), we often have to update the FAQ as well, which sort of ruins the convenience of the feature flag (being able to toggle a feature without manually removing it via a code change).

It would be nice if for certain questions, we display different answers based on what feature flags are enabled. If we're able to update our entire FAQ to work like this, future devs will only have to update the FAQ once and never worry about it again (unless a deadline is changed).

This is by no means urgent, but I think it's a change that would be good to eventually implement (even if it's after nwHacks 2019).