docs(router): fixed a typo in CanLoad title text (#27894)

 * Interface that a class can implement to be a guard deciding if a children can be loaded.
'...if a children...' changed to '...if children...'
 * Interface that a class can implement to be a guard deciding if children can be loaded.

PR Close #27894

packages/router/src/interfaces.ts

@@ -337,7 +337,7 @@ export interface Resolve<T> {
 /**
  * @description
  *
- * Interface that a class can implement to be a guard deciding if a children can be loaded.
+ * Interface that a class can implement to be a guard deciding if children can be loaded.
  *
  * ```
  * class UserToken {}