[LRR] lazy-loading page thumbnails

Author: URenko

comiclib/LANraragi/public/js/reader.js

@@ -715,7 +715,7 @@ Reader.initializeArchiveOverlay = function () {
         const thumbnail = `
             <div class='${thumbCss} quick-thumbnail' page='${index}' style='display: inline-block; cursor: pointer'>
                 <span class='page-number'>Page ${page}</span>
-                <img src="./img/wait_warmly.jpg" id="${index}_thumb" />
+                <img src="./img/wait_warmly.jpg" id="${index}_thumb" loading="lazy"/>
                 <i id="${index}_spinner" class="fa fa-4x fa-circle-notch fa-spin ttspinner" style="display:flex;justify-content: center; align-items: center;"></i>
             </div>`;