Allow overriding player cols & rows via query params

app/helpers/asciicasts_helper.rb

@@ -11,8 +11,8 @@ module AsciicastsHelper
     opts = {
       id: 'player',
       src: asciicast.url,
-      cols: asciicast.width,
-      rows: asciicast.height,
+      cols: options.cols || asciicast.width,
+      rows: options.rows || asciicast.height,
       poster: options.poster || base64_poster(asciicast),
       speed: options.speed,
       autoplay: options.autoplay,

app/models/playback_options.rb

@@ -23,6 +23,8 @@ class PlaybackOptions
   attribute :t,         Time
   attribute :v0,        Boolean, default: false
   attribute :poster,    String
+  attribute :cols,      Integer
+  attribute :rows,      Integer
 
   def autoplay()
     ap = super