v5.1.0

* Moved all script and style loading to `functions.php`.
* Added option to inline feature detection in the `<head>`.
* Added comment type to `wp_list_comments()` function in `comments.php`.
* Updated Sass structure for WP image styling.
* Added option to disable `wpautop`.
* Added option to remove loop pagination.
* Switched from `echo` to `?> content <?php` for echoing in `functions.php`.
* Updated `_config.scss` to match the version that ships with Kraken.
* Added helper methods to customize `the_excerpt()`.
* Added temporary fix for overzealous CSS injection by Jetpack.
* Removed some unused/unneeded classes from custom comment walker method.
* Added `.screen-reader-focusable` class to skip nav link.
* Renamed `keel.scss` to `main.scss`.
* Changed `#main` from `<section>` to `<main>`.