fix: missing pdfjs resources

public/index.html

@@ -50,6 +50,8 @@
 <script defer src="/static/js/highlight.min.js"></script>
 <script defer src="/static/js/interact.min.js"></script>
 <script defer src="/static/js/marked.min.js"></script>
+<script defer type="module" src="/static/js/pdfjs/pdf.mjs"></script>
+<script defer type="module" src="/static/js/pdf_viewer3.mjs"></script>
 <script defer src="/static/js/eventemitter3.umd.min.js"></script>
 <script defer src="/static/js/html2canvas.min.js"></script>
 <script defer src="/static/js/lsplugin.core.js"></script>