Add a short summary for every movie

- As suggested by @sindresorhus, I believe that adding a short summary (no more than 100-150 words) for every movie would be a very good idea. Right now, users need to jump around from link to link so as to find the right movie to watch.
- If anyone is willing to add a short summary (from IMDB?) to all the movies on the list, please let me know. 