Add the color-scheme meta tag (#523)

cuso4-5h2o

26.37.2021 68580148a3395a8762e0cab09ba574ff3dbcad4e

 layouts/_default/baseof.html

@@ -5,6 +5,8 @@
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="Content-Language" content="{{ .Site.Language.Lang }}">
    <meta name="color-scheme" content="light dark">
    
    {{ if .Site.Params.csp }}
      {{ partial "csp.html" . }}
    {{ end }}