update link to cover image

Author: bandinopla

index.html

@@ -7,7 +7,7 @@
     <meta name="twitter:card" content="summary_large_image">
     <meta name="twitter:site" content="@bandinopla">
     <meta name="twitter:title" content="Three.js - TSL Visual Node Editor">
-    <meta property="og:image" content="https://github.com/bandinopla/three.js-visual-node-editor/raw/main/cover.png">
+    <meta property="og:image" content="https://github.com/bandinopla/three.js-visual-node-editor/raw/main/public/cover.png">
     <title>Three.js - TSL Visual Node Editor </title>
     <style>
         html, body {