Create singleton and image generation

[bryanhce]

• tbh we don't really need to use singleton pattern as we truly call the reddit class once but its ok, we use it as learning and in the event in the future, we ever need to call it twice, the code will be more efficient
• create function to generate image containing the title of the post, but the func is not used in video generation yet as this would require some major refactoring of code
• see template.jpg to view what the image will look like