suggest to add a new particle design tools [Effekseer] to "Particle System" chapter

[drelaptop]

English Discuss: http://discuss.cocos2d-x.org/t/effekseer-particle-effect-editor-for-cocos2d-x/39772

中文讨论：http://forum.cocos.com/t/pu/58149

GitHub: https://github.com/effekseer/EffekseerForCocos2d-x

[slackmoehrle]

I started a new PR here that includes adding this tool. #147

[drelaptop]

great, I will translate those docs later.