fix(iam): add menu

Author: ldecarvalho-doc

menu/navigation.json

@@ -414,6 +414,10 @@
                     "label": "Permission sets",
                     "slug": "permission-sets"
                   },
+                  {
+                    "label": "IAM Guests to Members migration",
+                    "slug": "guests-to-members-migration"
+                  },
                   {
                     "label": "Reproducing roles and Project-scoped API keys with IAM",
                     "slug": "reproduce-roles-project-api-keys"