Update flags for vpa components automatically

[voelzmo]

Which component are you using?:
/area vertical-pod-autoscaler

Is your feature request designed to solve a problem? If so describe the problem this feature should solve.:
Keeping the flag documentation at https://github.com/kubernetes/autoscaler/blob/master/vertical-pod-autoscaler/docs/faq.md#what-are-the-parameters-to-vpa-recommender up-to-date is a manual effort, which is cumbersome and error-prone.

Describe the solution you'd like.:
We should auto-generate the flag docs similar to #7014

Options are: running it automatically in our CI or putting it into some make generate command and force PR authors to run this before they submit with a pre-check.

[adrianmoisey]

+1

I also want to generate the API documentations automatically, which is something I'm busy working on

[omerap12]

/assign

[omerap12]

Perhaps I'm mistaken, but it seems the documentation is not up to date. Having this script would be useful for keeping them current.