Fix no-preload for embed

app/helpers/asciicasts_helper.rb

@@ -17,12 +17,15 @@ module AsciicastsHelper
       speed: options.speed,
       autoplay: options.autoplay,
       loop: options.loop,
-      preload: options.preload,
       'start-at' => options.t,
       'font-size' => options.size,
       theme: options.theme,
     }
 
+    if options.preload # because {preload: false} gets converted to "preload=preload" by Rails
+      opts[:preload] = true
+    end
+
     unless skip_titlebar
       opts.merge!(
         title: asciicast.title,