Added fade out animation

content.css

@@ -58,6 +58,11 @@
 	  to { opacity: 1; }
 }
 
+@keyframes fadeOut {
+	from { opacity: 1; }
+	  to { opacity: 0; }
+}
+
 .sponsorBlockSpacer {
 	background-color: rgb(100, 100, 100);
 	border-color: rgb(100, 100, 100);
@@ -82,6 +87,10 @@
 	padding-right: 5px;
 }
 
+.sponsorBlockFadeOutAnimiation {
+	animation: fadeOut 3s;
+}
+
 .sponsorSkipNoticeTimeLeft {
 	color: #eeeeee;