feat(iam): note logs (#4016)

Author: ldecarvalho-doc

identity-and-access-management/iam/how-to/invite-user-to-orga.mdx

@@ -40,4 +40,7 @@ You can invite people to be IAM users of an Organization in which you are not th
     The user receives an email inviting them to accept your invitation. If they do not already have a Scaleway account, they will be prompted to [create one](/console/account/how-to/create-an-account/) first.
 6. The user will appear in the list of your Organization's users once they have accepted the invitation.
 
-
+<Message type="important">
+  Invitations have a validity period of 7 days.
+  Once an invitation expires, or if it is rejected, an [IAM log](/identity-and-access-management/iam/how-to/view-logs) is created indicating the user was "deleted".
+</Message>

identity-and-access-management/iam/how-to/view-logs.mdx

@@ -25,6 +25,7 @@ dates:
     Some of the principals who performed the actions might appear as `Unknown` in the logs. This could be due to a couple of reasons: <br />
     - The principal used to be a part of the Organization, but since performing the action is no longer a part of it. For example, if a user or an application is removed from an Organization, their name will no longer appear in the list, but the user or application ID still indicates it was them who performed the action.
     - You do not have the IAM permissions necessary to see the details of a principal.
+    - A user was deleted after the invitation to join an Organization was rejected or expired.
     <br />
 
     Besides `unknown`, you might also see principals named `Scaleway`. This happens when an action is performed by Scaleway. For example, whenever a new Organization is created 3 groups are created by default. This action is technically performed by Scaleway, and will be described as such in the logs.<br /><br />