Add IBM text and link as a sponsor (ko) (#3200)

Author: riseshia

ko/about/website/index.md

@@ -56,6 +56,8 @@ lang: ko
 
 <img src="../../../images/sponsor/works-on-arm.png" alt="Works on Arm" width="300" height="26" />
 
+[IBM][ibm] (호스팅)
+
 [Fastly][fastly] (CDN)
 
 <img src="../../../images/sponsor/fastly.png" alt="Fastly" width="200" height="200" />
@@ -78,6 +80,7 @@ lang: ko
 [rubyassociation]: http://www.ruby.or.jp
 [heroku]: https://www.heroku.com/
 [works-on-arm]: https://www.arm.com/markets/computing-infrastructure/works-on-arm
+[ibm]: https://www.ibm.com
 [fastly]: http://www.fastly.com
 [hatena]: http://hatenacorp.jp/
 [mackerel]: https://mackerel.io/