We can create a new post but we can't edit existing posts. To start we want the admin to click on a post and have it fill out the new
form so that we can edit it.
We will do this by listening for the slug. If it is new, then give us an empty form. If the slug is from one of our posts, then fill in the data of the post.
In the next lesson, we will take that data and fill out our form with it.