Update Configuration API

[ojhaujjwal]

A new way should be added to configure SimpleFileSystem Image loader

return [
    'htimg' => [
        'filters' => [
            'my_filter' => [
                'type' => 'filter_type',
                'options' => [
                    // .....
                    'image_loader' => 'simple',
                    'path'  => 'data/images/uploads', // this is the new part
                ]
            ]        
        ]
    ]
];