Document all annotations, labels used by ovn kubernetes across all features

[tssurya]

What would you like to see added/updated/deleted in our docs?

We add annotations and labels so often that there are no good docs, there are code comments in annotations files but that's it

Why is this needed?

I see this as a good opportunity to document our code base better

[github-actions]

This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 5 days.

[github-actions]

This issue was closed because it has been stalled for 5 days with no activity.