Create front end for post 'Likes' [Implementation]

[getinthedamnbox]

Whenever a post is displayed, the number of users who like it should be displayed alongside it. The state of the 'Like' button should be set based on if the current user likes the post. (For example, it should be blue if they like the post and gray otherwise.)

Also, the button should have different behavior based on its state. If the user does not like the post, the button should make a request to POST /like. If the current user likes the post, the button should make a request to DELETE /like.