feat(docs): Add SignOut.Restart details

src/content/docs/reference/policies/SignOut.mdx

@@ -6,8 +6,8 @@ category: "Authentication"
 
 Configure sign-out behavior for enterprise users.
 
-By default, shutting the browser down signs the session out, so the next launch requires the user to sign in again.
-Set this policy to lock the session on shutdown instead, so that returning users only need to unlock it.
+By default, shutting the browser down or restarting it for an update signs out the session, so the next launch requires the user to sign in again.
+Set this policy to lock the session instead, so that returning users only need to unlock it through operating system authentication rather than going through the full SSO sign-in.
 
 ## Values
 
@@ -16,6 +16,11 @@ Set this policy to lock the session on shutdown instead, so that returning users
     - `lock`: Lock the session, so the next launch only requires the user to unlock.
     - `signout`: Sign the session out, so the next launch requires a full sign-in.
       This is what happens when the policy is not set.
+- `Restart`: Controls what happens to the session when the browser restarts when applying a pending update.
+  - `Action`: (**required**) A string, one of:
+    - `lock`: Lock the session, so the next launch only requires the user to unlock.
+    - `signout`: Sign the session out, so the next launch requires a full sign-in.
+      This is what happens when the policy is not set.
 
 ## Examples