_layouts/redirect.html
<!doctype html>
<html>
<head>
<link rel="canonical" href="{{ page.redirect_to }}"/>
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<meta http-equiv="refresh" content="2;url={{ page.redirect_to }}" />
</head>
<body>
<h1>Redirecting...</h1>
<img src="https://media3.giphy.com/media/xjZtu4qi1biIo/giphy.gif" />
<a href="{{ page.redirect_to }}">Click here if you are not redirected.<a>
<script>setTimeout(() => {location='{{ page.redirect_to }}'}, 2000);</script>
</body>
</html>