Merge pull request #27575 from hashicorp/jan21_github_ksyun_removal

website: Remove links to legacy provider docs for GitHub, ksyun

website/docs/providers/index.html.markdown

@@ -33,9 +33,7 @@ the links below:
 - [Chef](/docs/providers/chef/index.html)
 - [Cobbler](/docs/providers/cobbler/index.html)
 - [Genymotion](/docs/providers/genymotion/index.html)
-- [GitHub](/docs/providers/github/index.html)
 - [Infoblox](/docs/providers/infoblox/index.html)
-- [KingsoftCloud](/docs/providers/ksyun/index.html)
 - [MySQL](/docs/providers/mysql/index.html)
 - [Rubrik](/docs/providers/rubrik/index.html)
 - [Rundeck](/docs/providers/rundeck/index.html)