[Docs] Missing documentation on ACLs

[coodos]

On graphql queries we don't currently show ACLs and it's only sent back on webhooks but it's not documented

[nsergey82]

A scenario where this could be a blocker -- a new platform scans an evault via graphql to bootstrap its database and must align the ACL on the vault with platform's ACL model in its DB. At this point those envelopes will not be brought by awareness through webhook.