Update README

Author: ehmicky

README.md

@@ -25,10 +25,12 @@ details") to use in an HTTP response.
 [`modern-errors`](https://github.com/ehmicky/modern-errors).
 
 ```js
-import modernErrors from 'modern-errors'
+import ModernError from 'modern-errors'
 import modernErrorsHttp from 'modern-errors-http'
 
-export const BaseError = modernErrors([modernErrorsHttp])
+export const BaseError = ModernError.subclass('BaseError', {
+  plugins: [modernErrorsHttp],
+})
 ```
 
 [Configuring](#configuration) error fields.
@@ -83,7 +85,7 @@ not `require()`.
 _Type_: `Plugin`
 
 Plugin object to
-[pass to `modernErrors()`](https://github.com/ehmicky/modern-errors#adding-plugins).
+[pass to the `plugins` option of `ErrorClass.subclass()`](https://github.com/ehmicky/modern-errors#adding-plugins).
 
 ## error.httpResponse()
 
@@ -153,34 +155,26 @@ set to an empty object.
 [Options](#options) can apply to (in priority order):
 
 - Any error: second argument to
-  [`modernErrors()`](https://github.com/ehmicky/modern-errors#modernerrorsplugins-options)
-
-```js
-export const BaseError = modernErrors(plugins, { http: { ...options } })
-```
-
-- Any error of multiple classes: using
-  [`ErrorClass.subclass()`](https://github.com/ehmicky/modern-errors#baseerrorsubclassname-options)
+  [`ModernError.subclass()`](https://github.com/ehmicky/modern-errors#options-1)
 
 ```js
-export const SharedError = BaseError.subclass('SharedError', {
+export const BaseError = ModernError.subclass('BaseError', {
+  plugins: [modernErrorsHttp],
   http: { ...options },
 })
-
-export const AuthError = SharedError.subclass('AuthError')
-export const InputError = SharedError.subclass('InputError')
 ```
 
-- Any error of a specific class: second argument to
-  [`BaseError.subclass()`](https://github.com/ehmicky/modern-errors#baseerrorsubclassname-options)
+- Any error of a specific class (and its subclasses): second argument to
+  [`ErrorClass.subclass()`](https://github.com/ehmicky/modern-errors#options-1)
 
 ```js
 export const AuthError = BaseError.subclass('AuthError', {
   http: { ...options },
 })
 ```
 
-- A specific error: second argument to the error's constructor
+- A specific error: second argument to
+  [`new ErrorClass()`](https://github.com/ehmicky/modern-errors#options-3)
 
 ```js
 throw new AuthError('...', { http: { ...options } })