Adds font awesome aria-hidden="true" to Wordpress allowed list of tags, mainly used to sanitize callback

font-awesome-sanitize-html.php

<?php /**
 * The force_balance_tags() function ensures that no tags are left unclosed, 
 * we're also using wp_kses to allow font awesome 'aria-hidden' tag to be allowed 
 *
 * @param int $input. 
 * @return int sanitizes html input to display output. force_balance_tags checks to see if any html tags are unclosed.
 */
function html_sanitize_text($input) {

	$filtered = wp_kses($unfiltered, $allowed_html, $allowed_protocols);

	$allowed_html = array( 
		'i' => array(
	        'class' => array(),
	        'aria-hidden' => array()
	    ),
	);

    return force_balance_tags( $input );
}