Querying the DOM

Exercises to cover selecting elements on the DOM.

Covers querySelector and querySelectorAll for finding elements by id,
class, tag name, and name attribute.

Also includes an exercise to learn the getElement(s)ByX methods.

Does not cover manipulating the DOM or reading properties of the elements. That will be a separate set of exercises.
Comparing results, most seemed to be about using `getElementByTagName`. I instead searched for `css selector find element by tag` and that had the answer in the first result.

So I guess this invalidates my previous comment.