Add SVG to allowed file uploads in Wordpress without plugin

functions.php

/**
* add SVG to allowed file uploads
**/
function add_file_types_to_uploads($file_types){

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

return $file_types;
}
add_action('upload_mimes', 'add_file_types_to_uploads');