better meta tags + image previews

view.php

@@ -17,6 +17,9 @@
     $wall = getwallpaper("https://wallhaven.cc/api/v1/w/$_GET[w]?apikey=$apikey");
     $_POST['wall'] = $wall["path"];
   }
+  /* set meta tag */
+  printf("<meta property='twitter:image:src' content='/proxy.php?i=%s'>", $_POST['wall']);
+  printf("<meta property='twitter:card' content='summary_large_image'>");
   /* get wallpaper id and get info from api */
   preg_match("/(?!.*-)([A-Za-z0-9]+)/", $_POST['wall'], $matches);
   if ($_POST['purity'] === "nsfw")