An annotation extension based on the PDF.js viewer. Supporting the editing of existing PDF file annotations, posting comments, replying, submitting annotation data, and loading for further editing. 一个基于 PDF.js 阅读器的批注扩展，支持对现有 PDF 文件批注的编辑、发布评论、回复、提交批注数据以及加载后续编辑功能。