Summary

Make a warning message show up when a user inputs a url into the new_link page that results in an HTTP error. This should show up as soon as the user clicks out of the field. Don't prohibit the user from submitting a link that results in an HTTP error (that's handled already- see #108 (closed)). 99% sure this has to be done in javascript.

Helpful Links

https://www.google.com/search?&q=javascript+instant+validation https://vuejs.org/v2/examples/firebase.html