* revise icon documentation
Screen readers would completley pass over the listing if icons as `<i class=“fa fa-*”></i>` largely means nothing to a screen reader.
Updated the example icons to have a `role=“img”` and `aria-label` to announce what type of icon was being represented.
In the `button` examples, added an `aria-hidden=“true”` attribute, so that the icons were not interpreted by screen readers.
Revised the wording of some parts of the documentation to make wording more concise.
* template accessibility updates
* remove “logo” from alt value. While the image is of the shoelace logo, it also serves as the heading to the website. So hearing “Shoelace logo” as the `h1` of the document is very strange.
* move the `main` element to a different location. Previously the `main` wrapped the navigation and the primary content of the document. This update moves the `main` to the primary content wrapper, to allow screen reader users a means to easily skip past the navigation.
* template updates round 2
* update shoelace link in footer to say “shoelace - home” rather than “shoelace logo”. being that this is a link, this provides better context that the link will take a user to the home page, rather than to a “shoelace logo”.
* add `aria-label` to twitter link to better align with github link announcements
* add `aria-current=“page”` via jQuery script. Now the current navigation item will be announced as “current page” to those that can’t see the `current` css class styling.
* Adds skip to link for keyboard users
* Makes navigation wrapper a nav element for screenreader support
* Adds role contentinfo to footer for screenreader support
* Built doc files
