So, Hello Hexo, and Goodbay Octopress

## why move from octopress to hexo

Speed is the main concern. Octopress can be very slow , while hexo is lightening fast.
Second reason is that i like this pretty theme Yilia. Many thanks to its author litten.

## What changed

#### mathjax

Some math formulas in my old octopress posts could not be rendered properly. So i changed contents of the file /themes/yilia/layout/_partial/mathjax.ejs to following:

Characters like _ and * must be manually escaped to get mathjax working properly.

#### D3, Impress.js, P5.js

Those amazing posts i wrote in octopress which used d3/impress/p5 could not work anymore. Currently i do not have much time to make them work in hexo(you known, final exams are coming!), but i will do this in future.