Add generator tag and comment link to theme code

How to preserve HTML comments in Go templates: https://discourse.gohugo.io/t/how-to-add-comments-in-a-template/75/8
há 6 anos · de8ccb0806
--- a/layouts/partials/header.html
+++ b/layouts/partials/header.html
@@ -2,6 +2,8 @@
 <html>
  <head>
    <title>{{ .Site.Title }}</title>
    {{ .Hugo.Generator }}
    {{ "<!-- Tumble theme for Hugo: https://github.com/adrianshort/tumble -->" | safeHTML }}
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="{{ relURL "/css/main.css" }}">
  </head>