Comment out HTML @Stephen1Chebon_twitter

<!-- we need to ensure that all of the given exercise code is retained. can you see what is missing? hint, review
the first & last lines of code. can you determine what is "commented out" by this code? how can it be adjusted to obtain the desired exercise result? -->

<h1>Hello World</h1><!-welcome-> <!-- why is this "welcome" structure here? also, is it a valid element (check format)? -->

<h2>CatPhotoApp</h2>

<p>Kitty ipsum dolor sit amet, shed everywhere shed everywhere stretching attack your ankles chase the red dot, hairball run catnip eat the grass sniff.</p><!-description-> <!-- why is this "description" structure here? is it valid (same as above) -->