Add playback: playing: false default to scripts, with default editor task to adjust it

app/lib/DefaultScripts.coffee

@@ -15,6 +15,8 @@ module.exports = [
           play: true
       script:
         duration: 1
+      playback:
+        playing: false
     ]
   }
 ]

app/schemas/models/level.coffee

@@ -14,6 +14,7 @@ defaultTasks = [
   'Do basic set decoration.'
   'Adjust script camera bounds.'
   'Choose music file in Introduction script.'
+  'Choose autoplay in Introduction script.'
 
   'Add to a campaign.'
   'Publish.'