Enhancement: Include gif in readme

[pykong]

Make the proposition/advantage/selling point of TabNine clearer. Instead of elaborate sales script. What about including a picture or animated gif contrasting the autocompletion with and without TabNine? Include that in the README so it will appear on TabNine's packagecontrol site as well.

Such visual content would immediately communicate what TabNine can do for you.

As an inspiration see how the folks behind Kite do it: https://youtu.be/bF50YPyUKTQ?t=87

[zxqfl]

This is a good idea, thanks for the link. It would be nice to compare against both built-in editor autocompletion and ycmd.