Pull multiple tags of API ref and bundle openAPI schema

[domire8]

yes you are right that these are both outdated. api-server-docs is the newer image and v4.3.2 is the latest. For now l would say to use api-server-docs:latest as the image of choice, but that we add a new issue to take care of this properly:

I think we should:

• always pull latest for the default API reference link
• also pull multiple older tags of the image and put them in respectively tags subdirectories so that we can include version-specific links in a dropdown
  • I think we can just manually set the latest of each prior major release, so e.g. 3.4.1, then 4.X before v5, etc, while latest is always latest
• also bundle our openAPI schema in the image so that we distribute it more easily

Originally posted by @eeberhard in #255 (comment)