SB: Binding Doc Update

[ralikio]

AC

• 1) Add new doc for contributor/Service Binding Details -
  • 1.1) Add to documentation info about how we find out which bindings are to be removed. "Service Binding states are not required, we can delete objects by determining expires_at and kubeconfig fields. If expires_at is older than the current time, SB should be deleted". - snippet from SB: Service Binding for Kyma Service Instance - Epic #284 (comment). - state is too much of a details
  • 1.2) "kubeconfig value determines SB state. If it's empty, SB is in an unknown state, it may be in progress (max 800ms) or error" - snippet from SB: Service Binding for Kyma Service Instance - Epic #284 (comment)
• 2) Enahce docs/user/05-60-kyma-bindings.md with user facing features/behaviours, e.g.
  • 2.1) Not Expired SB limits
  • 2.2) 404 if expired of get
  • 2.3) Describe how and where KEB creates SA, CRB, CR in the SKR