docs(sponsors): add opencollective

docs/sponsors.md

@@ -15,12 +15,22 @@ description: "The companies or individuals contributing a monthly amount to help
 SpaceVim is an open source project.
 Currently, this project is maintained by [@wsdjeg](https://github.com/wsdjeg),
 If you use SpaceVim in your daily work and feel that it has made your life easier,
-please consider supporting SpaceVim by buy me a coffee:
+please consider supporting SpaceVim by:
+
+- [Become a backer on opencollective](https://opencollective.com/spacevim)
+
+Also, you can buy me a coffee:
 
 <a href='https://ko-fi.com/SpaceVim' target='_blank'><img height='36' style='border:0px;height:36px;' src='https://az743702.vo.msecnd.net/cdn/kofi4.png?v=f' border='0' alt='Buy Me a Coffee at ko-fi.com' /></a>
 
+| wechat                                                                   | alipay                                                                     |
+| ------------------------------------------------------------------------ | -------------------------------------------------------------------------- |
+| <img src="https://spacevim.org/img/weixin.png" height="150" width="150"> | <img src="https://spacevim.org/img/zhifubao.png" height="150" width="150"> |
+
 ## Backers
 
+These are the companies or individuals contributing a monthly amount to help sustain SpaceVim's development.
+
 | Date         | Amount   | Description              |
 | ------------ | -------- | ------------------------ |
 | 2016-09-26   | ¥ 100    | \*好                     |