feat: use favicon ico

Author: Lewis Youl

app/assets/images/favicon.ico

@@ -22,7 +22,7 @@
 
     <meta name="turbolinks-cache-control" content="no-preview">
 
-    <%= favicon_link_tag asset_path("logo_square.png") %>
+    <%= favicon_link_tag %>
     <%# <script src="//cdnjs.cloudflare.com/ajax/libs/highlight.js/10.0.1/highlight.min.js"></script> %>
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/cropperjs/1.5.9/cropper.min.css" integrity="sha512-w+u2vZqMNUVngx+0GVZYM21Qm093kAexjueWOv9e9nIeYJb1iEfiHC7Y+VvmP/tviQyA5IR32mwN/5hTEJx6Ng==" crossorigin="anonymous" />
     <script src="https://cdnjs.cloudflare.com/ajax/libs/cropperjs/1.5.9/cropper.min.js" integrity="sha512-9pGiHYK23sqK5Zm0oF45sNBAX/JqbZEP7bSDHyt+nT3GddF+VFIcYNqREt0GDpmFVZI3LZ17Zu9nMMc9iktkCw==" crossorigin="anonymous"></script>