composer require symfony/css-selector:6.0.2
composer require nodeloc/flarum-ext-signature:*
把下面的代码自定义CSS里，注意图片路径！
/* 签名 */
.Post-footer .item-signature .Signature { font-size: 13px;color: #999 !important;background: url(/assets/files/bio.png) left top no-repeat;padding-top: 20px;}
.Post-footer .item-signature .Signature .Signature-content { margin-bottom: 0;max-height: 45px;overflow: hidden;}
.Post-footer .item-signature .Signature .Signature-content { padding-top: 3px;border-top: 1px dashed #808080;
opacity: 0.5;transition: opacity .3s ease;}
