app/views/layouts/application.html.erb
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title><%= content_for?(:title) ? yield(:title) : "Media Blog" %></title>
<meta name="description" content="<%= content_for?(:description) ? yield(:description) : "Media Blog" %>">
<%= stylesheet_link_tag "application", media: "all", "data-turbolinks-track" => true %>
<%= javascript_include_tag "application", "data-turbolinks-track" => true %>
<%= csrf_meta_tags %>
</head>
<body class="<%= controller.controller_name.dasherize %> <%= controller.action_name.dasherize %>">
<header>
<%= render 'layouts/navigation' %>
</header>
<main role="main">
<%= render 'layouts/messages' %>
<%= yield %>
</main>
</body>
</html>