add notes about AuthErrorHttpHandler into README.md

README.md

@@ -359,8 +359,9 @@ There are several ways to adjust functionality of the library:
 1. `ClaimsUpdater` - interface with `Update(claims Claims) Claims` method. This is the primary way to alter a token at login time and add any attributes, set ip, email, admin status, roles and so on.
 1. `Validator` - interface with `Validate(token string, claims Claims) bool` method. This is post-token hook and will be called on **each request** wrapped with `Auth` middleware. This will be the place for special logic to reject some tokens or users.
 1. `UserUpdater` - interface with `Update(claims token.User) token.User` method.  This method will be called on **each request** wrapped with `UpdateUser` middleware. This will be the place for special logic modify User Info in request context. [Example of usage.](https://github.com/go-pkgz/auth/blob/19c1b6d26608494955a4480f8f6165af85b1deab/_example/main.go#L189)
+1. `AuthErrorHttpHandler` - interface with `ServeAuthError(w http.ResponseWriter, r *http.Request, and other params)` method. It is possible to change how authentication errors are written into HTTP responses by configuring custom implementations of this interface for the middlewares.
 
-All of the interfaces above have corresponding Func adapters - `SecretFunc`, `ClaimsUpdFunc`, `ValidatorFunc` and `UserUpdFunc`.
+Some of the interfaces above have corresponding Func adapters - `SecretFunc`, `ClaimsUpdFunc`, `ValidatorFunc` and `UserUpdFunc`.
 
 ### Implementing black list logic or some other filters