carrying over conversation on twitter with @steven-tey
when someone hits a link that 404s, it would be helpful to know what link they were trying to access so that we can try and recover another way.
For example, if someone tries to go to hypothetical.link/12345 and that link doesnt exist, when they are redirected to our 404 page (eg. hypothetical.link/not-found) it would be awesome to know what they were originally trying to reach so that we can dynamically serve the correct content (eg. hypothetical.link/not-found&src=12345)