Add Peer auto-grouping doc

docs/overview/acls.md

@@ -30,6 +30,10 @@ Some characteristics of groups:
 - They can only be deleted via API.
 - There is a default group called `All`.
 
+:::tip peer auto-grouping
+You can assign groups automatically with the [peer auto-grouping feature](/overview/setup-keys#peer-auto-grouping).
+:::
+
 ### The All Group
 The `All` group is a default group to which every peer in your network is automatically added to. This group cannot be modified or deleted.
 ### Rules
@@ -92,6 +96,10 @@ You can do it by accessing the `Peers` tab and clicking the `Groups` column of a
     <img src="/docs/img/overview/associate-peer-groups.png" alt="high-level-dia" width="300" style={{boxShadow: '0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19)'}} />
 </p>
 
+:::tip peer auto-grouping
+You can assign groups automatically with the [peer auto-grouping feature](/overview/setup-keys#peer-auto-grouping).
+:::
+
 ### Updating Rules
 To update a rule, you can click on the rule's `Name` or on either `Sources` and `Destinations` columns. You could also click the menu 
 button of a rule and select `View`. This will open the same screen where you can update rule groups, description, or status.

docs/overview/setup-keys.md

@@ -34,3 +34,28 @@ When revoking a key, all machines authenticated with this key will remain connec
 ### Expiration
 
 Setup keys are set to expire after 30 days. When expired, the setup key can't be used anymore.
+
+### Peer Auto-grouping
+
+<p align="center">
+    <img src="/docs/img/architecture/peer-auto-tagging-setupkey.gif" alt="high-level-dia" width="800" style={{boxShadow: '0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19)'}} />
+</p>
+
+NetBird offers a powerful [Access Control feature](/overview/acls) that allows easy access management of your resources. 
+In a basic scenario, you would create multiple groups of peers and create access rules to define what groups can access each other. 
+Adding peers to groups might become time-consuming in large networks with dozens of machines.
+
+Starting NetBird [v0.9.2](https://github.com/netbirdio/netbird/releases), when creating or updating a setup key, 
+it is possible to specify a list of auto-assign groups. Every peer registered with this key will be automatically added 
+to these groups. All the access control rules enabled for these groups will apply automatically.
+
+To add `Auto-assign groups`, open the `Setup Keys` tab and create or update any existing setup key. 
+The use this key to enroll new machine.
+
+<p align="center">
+    <img src="/docs/img/architecture/netbird-peer-auto-tagging-newkey.png" alt="high-level-dia" width="600" style={{boxShadow: '0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19)'}} />
+</p>
+
+:::note
+Auto-assign groups will apply only to newly registered machines.
+:::