Add favicon to landing page

Author: doradocodes

docs/index.html

@@ -5,6 +5,7 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Processing Collaborative Editor</title>
+    <link rel="icon" href="./assets/Processing_2021_logo_512x512.png" type="image/png">
 
     <style>
         @import url('https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&family=Space+Grotesk:wght@300..700&display=swap');