docs: Add doc for container ACL field

ACL support still under development. Detailed documentation on
container access rules will be added later.

docs/container.md

@@ -21,6 +21,8 @@
 - [container/types.proto](#container/types.proto)
 
   - Messages
+    - [AccessControlList](#container.AccessControlList)
+    - [AccessGroup](#container.AccessGroup)
     - [Container](#container.Container)
     
 
@@ -164,6 +166,7 @@ via consensus in inner ring nodes
 | Capacity | [uint64](#uint64) |  | Capacity defines amount of data that can be stored in the container (doesn't used for now). |
 | OwnerID | [bytes](#bytes) |  | OwnerID is a wallet address |
 | rules | [netmap.PlacementRule](#netmap.PlacementRule) |  | Rules define storage policy for the object inside the container. |
+| Group | [AccessGroup](#container.AccessGroup) |  | Container ACL. |
 | Meta | [service.RequestMetaHeader](#service.RequestMetaHeader) |  | RequestMetaHeader contains information about request meta headers (should be embedded into message) |
 | Verify | [service.RequestVerificationHeader](#service.RequestVerificationHeader) |  | RequestVerificationHeader is a set of signatures of every NeoFS Node that processed request (should be embedded into message) |
 
@@ -193,6 +196,29 @@ via consensus in inner ring nodes
  <!-- end services -->
 
 
+<a name="container.AccessControlList"></a>
+
+### Message AccessControlList
+
+
+
+| Field | Type | Label | Description |
+| ----- | ---- | ----- | ----------- |
+| List | [AccessGroup](#container.AccessGroup) | repeated | List of access groups. |
+
+
+<a name="container.AccessGroup"></a>
+
+### Message AccessGroup
+
+
+
+| Field | Type | Label | Description |
+| ----- | ---- | ----- | ----------- |
+| AccessMode | [uint32](#uint32) |  | Group access mode. |
+| UserGroup | [bytes](#bytes) | repeated | Group members. |
+
+
 <a name="container.Container"></a>
 
 ### Message Container
@@ -205,6 +231,7 @@ The Container service definition.
 | Salt | [bytes](#bytes) |  | Salt is a nonce for unique container id calculation. |
 | Capacity | [uint64](#uint64) |  | Capacity defines amount of data that can be stored in the container (doesn't used for now). |
 | Rules | [netmap.PlacementRule](#netmap.PlacementRule) |  | Rules define storage policy for the object inside the container. |
+| List | [AccessControlList](#container.AccessControlList) |  | Container ACL. |
 
  <!-- end messages -->