Update index.html

Author: Gmac4247

index.html

@@ -11,6 +11,7 @@
 <link rel="icon" type="image/x-icon" href="favicon.ico">
 <link rel="mask-icon" href="safari-pinned-tab.svg" color="#000000">
 <link rel="manifest" href="manifest.json">
+<link rel="canonical" href="https://basic-geometry.github.io">
 <link href="https://fonts.googleapis.com/css2?family=OpenDyslexic&display=swap" rel="stylesheet">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <meta name="author" content="Gaál Sándor">