🤗 re-write the example of ErrorHandler from type assertion to errors.As #1938
Description
This is more a suggestion than a question.
Lines 75 to 85 in 43aa457
this would be better to use errors.As to fit go error handling style
// ErrorHandler defines a function that will process all errors
// returned from any handlers in the stack
// cfg := fiber.Config{}
// cfg.ErrorHandler = func(c *Ctx, err error) error {
// code := StatusInternalServerError
// var e *fiber.Err
// if errors.As(err, &e) {
// code = e.Code
// }
// c.Set(HeaderContentType, MIMETextPlainCharsetUTF8)
// return c.Status(code).SendString(err.Error())
// }
// app := fiber.New(cfg)
type ErrorHandler = func(*Ctx, error) error