fix broken document

packages/core/src/utils/isList.ts

@@ -1,5 +1,6 @@
 import { Extensions } from '../types'
 import splitExtensions from './splitExtensions'
+import callOrReturn from './callOrReturn'
 
 export default function isList(name: string, extensions: Extensions) {
   const { nodeExtensions } = splitExtensions(extensions)
@@ -9,5 +10,11 @@ export default function isList(name: string, extensions: Extensions) {
     return false
   }
 
-  return extension.group === 'list'
+  const groups = callOrReturn(extension.group, { options: extension.options })
+
+  if (typeof groups !== 'string') {
+    return false
+  }
+
+  return groups.split(' ').includes('list')
 }