Update _posts/2013-01-11-dynamic-videos.md

- Video is played as part of the video player and 
dynamically reloading the video player instance on every new video will not produce satisfactory user experience.
Dear Sergey Yurevich, please review the following sentences: 

- After modifying the source, I found that the video player still was in the pause mode and the way to play the video after the source was changed was only by calling play() method.

- In order to consistently deliver achieve this ETA, I'm working on video pre-loading technology, which will allow loading videos for further interactions while the user is engaged with previous steps.