Add favicon and enhance content structure

- Added a favicon link to both index.html and links.html.
- Wrapped main content in a div for better structure in index.html.
- Updated footer links to open in new tabs and added new links in links.html.
- Introduced new CSS classes for song cover and mini text styling.

style.css

@@ -58,4 +58,20 @@ a {
     image-rendering: pixelated;
     margin: 1px;
     display: inline;
+}
+.song-cover {
+    height: 200px;
+    width: auto;
+}
+.mini-text {
+    color: #fff;
+    font-size: 12px;
+    font-style: italic;
+    text-align: center;
+}
+.music audio {
+    width: auto;
+    height: auto;
+    align-items: center;
+    justify-content: center;
 }