Added IP Addresses Assign shared IP restriction

Author: bbiggerr

openapi.yaml

@@ -12423,6 +12423,7 @@ paths:
         * All Linodes involved must have at least one public IPv4 address after assignment.
         * Linodes may have no more than one assigned private IPv4 address.
         * Linodes may have no more than one assigned IPv6 range.
+        * Shared IP addresses cannot be swapped between Linodes.
 
         [Open a Support Ticket](/docs/api/support/#support-ticket-open) to request additional IPv4 addresses or IPv6 ranges beyond standard account limits.