_includes/head/custom.html

<!-- start custom head snippets -->

<!-- insert favicons. use https://realfavicongenerator.net/ -->
<link rel="icon" type="image/x-icon" href="{{site.baseurl}}/assets/favicon.ico">
<link rel="shortcut icon" type="image/x-icon" href="{{site.baseurl}}/assets/favicon.ico">
<!-- end custom head snippets -->