hugo-theme-relearn/layouts/partials/favicon.html

    {{- $assetBusting := not .Site.Params.disableAssetsBusting }}
    {{- if or (fileExists "/static/images/favicon-light.svg") (fileExists "/static/images/favicon-dark.svg") }}
    {{/*
      Warning: IE and old browser versions do not support media queries necessary for the light & dark theme option.
      If you have requirements to support IE and/or older browser versions, use one of the other options.
      Reference: https://caniuse.com/css-media-interaction
    */}}
    {{- if (fileExists "/static/images/favicon-light.svg") }}
    <link href="{{ "images/favicon-light.svg" | relURL }}{{ if $assetBusting }}?{{ now.Unix }}{{ end }}" rel="icon" type="image/svg+xml" media="(prefers-color-scheme: light)">
    {{- end }}
    {{- if (fileExists "/static/images/favicon-dark.svg") }}
    <link href="{{ "images/favicon-dark.svg" | relURL }}{{ if $assetBusting }}?{{ now.Unix }}{{ end }}" rel="icon" type="image/svg+xml" media="(prefers-color-scheme: dark)">
    {{- end }}
    {{- else if (fileExists "/static/images/favicon.svg") }}
    <link href="{{ "images/favicon.svg" | relURL }}{{ if $assetBusting }}?{{ now.Unix }}{{ end }}" rel="icon" type="image/svg+xml">
    {{- else if (fileExists "/static/images/favicon.png") }}
    <link href="{{ "images/favicon.png" | relURL }}{{ if $assetBusting }}?{{ now.Unix }}{{ end }}" rel="icon" type="image/png">
    {{- else if (fileExists "/static/images/favicon.ico") }}
    <link href="{{ "images/favicon.ico" | relURL }}{{ if $assetBusting }}?{{ now.Unix }}{{ end }}" rel="icon" type="image/x-icon">
    {{- else if (fileExists "/static/images/logo.svg") }}
    <link href="{{ "images/logo.svg" | relURL }}{{ if $assetBusting }}?{{ now.Unix }}{{ end }}" rel="icon" type="image/svg+xml">
    {{- else if (fileExists "/static/images/logo.png") }}
    <link href="{{ "images/logo.png" | relURL }}{{ if $assetBusting }}?{{ now.Unix }}{{ end }}" rel="icon" type="image/png">
    {{- else if (fileExists "/static/images/logo.ico") }}
    <link href="{{ "images/logo.ico" | relURL }}{{ if $assetBusting }}?{{ now.Unix }}{{ end }}" rel="icon" type="image/x-icon">
    {{- end }}