feat: add paste id for showlink

lib/ketbin_web/controllers/page_controller.ex

@@ -41,7 +41,8 @@ defmodule KetbinWeb.PageController do
     render(conn, "show.html",
       paste: paste,
       show_edit: show_edit,
-      extension: if(tail == [], do: "", else: tail)
+      extension: if(tail == [], do: "", else: tail),
+      page_title: paste.id
     )
   end