docs(authorization): replaces comment with hint

Author: stalniy

content/security/authorization.md

@@ -260,9 +260,11 @@ export class CaslAbilityFactory {
 
 > warning **Notice** `all` is a special keyword in CASL that represents "any subject".
 
-> info **Hint** `Ability`, `AbilityBuilder`, and `AbilityClass` classes are exported from the `@casl/ability` package.
+> info **Hint** `Ability`, `AbilityBuilder`, `AbilityClass`, and `ExtractSubjectType` classes are exported from the `@casl/ability` package.
 
-In the example above, we created the `Ability` instance using the `AbilityBuilder` class. As you probably guessed, `can` and `cannot` accept the same arguments but has different meanings, `can` allows to do an action on the specified subject and `cannot` forbids. Both may accept up to 4 arguments. To learn more about these functions, visit the official [CASL documentation](https://casl.js.org/v5/en/guide/intro). 
+> info **Hint** `detectSubjectType` option let CASL understand how to get subject type out of an object. Read the official [CASL documentation](https://casl.js.org/v5/en/guide/subject-type-detection#use-classes-as-subject-types) for details.
+
+In the example above, we created the `Ability` instance using the `AbilityBuilder` class. As you probably guessed, `can` and `cannot` accept the same arguments but has different meanings, `can` allows to do an action on the specified subject and `cannot` forbids. Both may accept up to 4 arguments. To learn more about these functions, visit the official [CASL documentation](https://casl.js.org/v5/en/guide/intro).
 
 Lastly, make sure to add the `CaslAbilityFactory` to the `providers` and `exports` arrays in the `CaslModule` module definition: