Update readme.
Update readme.

oomusou/hexo-theme-openmind,chenzaichun/hexo-theme-freemind,wzpan/hexo-theme-freemind,yieme/hexo-theme-freewill,zhi1ong/hexo-theme-freemind,leesei/hexo-theme-freemind,JoshuaZe/freemind,wzpan/hexo-theme-freemind,leesei/hexo-theme-freemind,blackshow/hexo-theme-freemind.386