add last_modified_at meta for http refresh cache

scaffold.rb

@@ -86,6 +86,7 @@
 settings["footer"] = Liquid::Template.parse(settings["footer"]).render(settings)
 settings["tagline"] = Liquid::Template.parse(settings["tagline"]).render(settings)
 settings["name"] = Liquid::Template.parse(settings["name"]).render(settings)
+settings["last_modified_at"] = Time.now.strftime("%Y-%m-%dT%H:%M:%S%z")
 
 # Parse the Liquid template
 liquid_template = Liquid::Template.parse(template_content)

themes/default/index.html

@@ -5,7 +5,8 @@
   <meta name="viewport" content="width=device-width, initial-scale=1.0" />
   <title>{{ title }}</title>
 
-  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
+  <meta charset="UTF-8">
+  <meta name="last-modified" content="{{ last_modified_at }}">
   <meta name="theme-color" media="(prefers-color-scheme: light)" content="#f7f7f7">
   <meta name="theme-color" media="(prefers-color-scheme: dark)" content="#1b1b1e">
   <meta name="apple-mobile-web-app-capable" content="yes">