Add CI task "Update /features page in docs from naas Readme.md"

[jravenel]

@chicken-biryani was not present in your gdoc, but same idea: readme and page in the doc should be the same and hence be automated.

Current: https://docs.naas.ai/features
Source: https://github.com/jupyter-naas/naas/blob/main/README.md
Target: https://github.com/jupyter-naas/docs/blob/master/features/README.md