Better documentation of elements

#76 brought up the point that it's difficult for new HTML users to understand how to use some of the more complicated HTML elements.

I'd love to see `index.html` (or maybe a separate page) have some sections on how to use each of the elements water.css supports. For example, documentation for the blockquote element could be:

---
### Blockquote
[Documentation](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/blockquote)

Example usage:
```

Words can be like X-rays, if you use them properly – they'll go through anything. You read and you're pierced.

– Aldous Huxley, Brave New World

Words can be like X-rays, if you use them properly – they'll go through anything. You read and you're pierced.

– Aldous Huxley, Brave New World

---

There would be a few parts to this issue:
1. Discussion on what the content documentation should contain?
2. Discussion on what the documentation should look like visually?
3. Writing of the html for this documentation

This is a lot of work to do, so any help on this issue is very appreciated!

Start with index.html and review whether a separate page better fits the proposed documentation. Define the content and visual approach, then add sections for each supported HTML element with an external documentation link, example markup, and rendered demo; completion means the supported elements are documented for new HTML users.

Written by the indexing model from the issue text.