feat: flex component, document higher-order layout components

Jacky Zhao

2025-03-11 2718ab90194b3c7be600d1a2dadc4250207db1c0

 docs/advanced/making plugins.md

@@ -99,8 +99,6 @@
            },
          ],
        }
      } else {
        return {}
      }
    },
  }