Additional Functions php

<?php
 /**
* Allow additional MIME types
* Use 'text/plain' instead of 'application/json' for JSON because of a current WordPress core bug
*/
function add_upload_mimes( $types ) { 
	$types['json'] = 'text/plain';
	return $types;
}
add_filter( 'upload_mimes', 'add_upload_mimes' );

<?php
/**
 * Add SVGs to the list of allowed mime types.
 * 
 * @param array $upload_mimes The existing allowed mime types.
 * 
 * @return array The enhanced allowed mime types.
 */
function gomo_admin_add_svg_to_upload_mimes( $upload_mimes ) {

    $file_types = array();
    $file_types['svg'] = 'image/svg+xml';
    $upload_mimes = array_merge( $file_types, $upload_mimes );
    return $upload_mimes;

}
add_filter('upload_mimes', 'gomo_admin_add_svg_to_upload_mimes');

<?xml version="1.0" encoding="utf-8"?>