Update README
Prevent comment form from refreshing on submission

The comment form has an id of `#new_comment`. We can use this to bind
to the form’s submit event. The code inside our function will run when
the `submit` event is triggered.

The first thing that we will want to do is prevent the form from
actually submitting, which would cause the page to refresh.
Adding a comment to the feed - part 1

Our end goal is to be able to add our new comment to the page without
having to refresh the page. We can start working toward that goal by
creating a String that represents a comment. Then we can find the
`<div>` that contains all of the comments by it’s class
`.comment-feed`. Finally, we can use jQuery’s
[.append()](https://api.jquery.com/append/) to append our comment to
the comment feed.
Create DOM elements for comment

We want our newly added comments to match the style of the other
comments on the page.

The HTML for the other comments looks something like this:

```html
<div class="comment">
  <h4>Eric</h4>
  <p>Hello world</p>
</div>
```

We can use jQuery to create DOM elements as shown in the sample above.
Instead of appending a string to the comment feed, we can append the
DOM element that we just created onto the page.
Create the comment asynchronously

Rather than hard coding the data, we want to use jQuery’s
[.ajax()](https://api.jquery.com/jQuery.ajax/) function to send a POST
request to `/posts/:id/comments` that includes all of the data in our
form. When the request finishes, either the `success` or the `failure`
callback function will run, depending on the [HTTP status
code](http://en.wikipedia.org/wiki/List_of_HTTP_status_codes) of the
response that the server sends back.

Usually our requests to the server are sending back HTML as the body of
the response. In order to configure the server to send back JSON as the
response, you need to change your controller a little bit. This has
already been done for you but you should go check out the
`CommentsController` to see how it works.
Check out the response

Swap our the alert in the `success` callback with a `debugger;` statement.
This works like pry in Ruby does. The only trick is that you need to have the
Javascript Console open when you submit the comment form.

> Hint: You can open the Javascript Console with `cmd + option + J`.

Try creating a comment with the Javascript Console open. Once you're in the
debugging session, type `response` into the Javascript Console to see the value
of the response that was returned from the server.

It looks like our hard coded object!
Add the real comment onto the page :boom:

Since the `response` is a JSON hash that represents the comment created
in the database, we can use this in place of our hard coded comment
attributes object. The easiest way to do this is to move all of the
code responsible for adding the comment to the page into the `success`
callback.