Initial Commit: wp-theme scaffold & initial art rendering

* Render thumbnails from custom post types in the header if you're on the homepage

Other Notes

* Scaffold created with 10up's `wp-theme` Grunt-init template
* Static assets built to & enqueue'd from /assets/build
* Theme altered to be a child theme of twentyeleven
* `gallery.php` template part added to render thumbnails from Artwork post type
* `gallery.php` included from within header.php
* Move Gruntfile's JSHint options out into a `.jshintrc` file
Initial, PHP-heavy solution to the artwork gallery UI

This approach favors rendering all of the content using WordPress, and only leveraging JS/jQuery to show and hide elements when handling user interaction