add comment to config snippet

[bnomei]

i copied the snippet but decided to change the blueprint name and forgot about the config value since everything else seemed to work. a small comment (not just the information in the sentence above the snippet) could help spot this mistake later on.

return [
    'sylvainjule.bouncer.list' => [
        'test' => [ // match the filename without extension of the user blueprint
            'fieldname' => 'canaccess'
        ]
    ]
];

[sylvainjule]

Added, thanks! ✓