Add https://www.cxist.com/ to powered-by page (#2251)

* Update powered-by.md

* Update powered-by.md

Change list order.

docs/powered-by.md

@@ -17,6 +17,7 @@ or providing commercial products including Apache SkyWalking.
 1. Chehejia Automotive. 北京车和家信息技术有限责任公司. https://www.chehejia.com/
 1. Chinadaas. 北京中数智汇科技股份有限公司. https://www.chinadaas.com/
 1. Cmft.com. 招商局金融科技. https://www.cmft.com/
+1. CXIST.com 上海程析智能科技有限公司 https://www.cxist.com/
 1. Dangdang.com. 当当网. http://www.dangdang.com/
 1. DaoCloud. https://www.daocloud.io/
 1. Deyoushenghuo in WeChat app. 河南有态度信息科技有限公司，微信小程序：得有生活