Make many of the improvements suggested in review.

lib/pleroma/web/templates/layout/static_fe.html.eex

@@ -4,7 +4,7 @@
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width,initial-scale=1,minimal-ui" />
     <title>
-    <%= Application.get_env(:pleroma, :instance)[:name] %>
+    <%= Pleroma.Config.get([:instance, :name]) %>
     </title>
     <link rel="stylesheet" href="/static/static-fe.css">
   </head>

lib/pleroma/web/templates/static_fe/static_fe/conversation.html.eex

@@ -1,5 +1,5 @@
 <header>
-  <h1><%= link @instance_name, to: "/" %></h1>
+  <h1><%= link instance_name(), to: "/" %></h1>
 </header>
 
 <main>

lib/pleroma/web/templates/static_fe/static_fe/profile.html.eex

@@ -1,5 +1,5 @@
 <header>
-  <h1><%= link @instance_name, to: "/" %></h1>
+  <h1><%= link instance_name(), to: "/" %></h1>
 
   <h3>
     <form class="pull-right collapse" method="POST" action="<%= Helpers.util_path(@conn, :remote_subscribe) %>">