try to load more lazy loaded contents

lib/single-file/single-file-core.js

@@ -283,6 +283,20 @@ const SingleFileCore = (() => {
 			this.doc.querySelectorAll("img[data-src]").forEach(imgElement => {
 				if (imgElement.dataset.src && imgElement.src != imgElement.dataset.src) {
 					imgElement.src = imgElement.dataset.src;
+					imgElement.removeAttribute("data-src");
+				}
+			});
+			this.doc.querySelectorAll("[data-bg]").forEach(element => {
+				if (element.dataset.bg && !element.style.backgroundImage.includes(element.dataset.bg)) {
+					element.style.backgroundImage = "url(" + element.dataset.bg + ")";
+					element.removeAttribute("data-bg");
+				}
+			});
+			this.doc.querySelectorAll("[data-srcset]").forEach(imgElement => {
+				if (imgElement.dataset.srcset && imgElement.srcset != imgElement.dataset.srcset) {
+					imgElement.srcset = imgElement.dataset.srcset;
+					imgElement.removeAttribute("data-srcset");
+					imgElement.classList.remove("no-src");
 				}
 			});
 		}