Optimize inline image with jpegoptim

I have tried both `jpegoptim` and `jpegtran`. They both gave the same results.

I've used:

    jpegoptim --strip-all --size=90% <imagefile>

Which optimize the images on 90% of its original state.
It produced a 10.82% smaller image.

In response to: https://github.com/limetext/limetext.github.io/pull/7#issuecomment-29532936