Incorrect example of Protocol type check in documentation

<!-- Please describe the problem or your idea or suggestion below. Please include the URL of the page this issue is about, if applicable. --> On the page "Protocols — typing documentation" in section ["`type[]` and class objects vs protocols"](https://typing.python.org/en/latest/spec/protocol.html#type-and-class-objects-vs-protocols) is given wrong example: instead of class instances are given class references. Even more, error and success cases are mismatched: ```python from typing import Any, Protocol class ProtoA(Protocol): def meth(self, x: int) -> int: ... class ProtoB(Protocol): def meth(self, obj: Any, x: int) -> int: ... class C: def meth(self, x: int) -> int: ... a: ProtoA = C # Type check error, signatures don't match! b: ProtoB = C # OK ``` Should be this: ```python a: ProtoA = C() # OK b: ProtoB = C() # Error ```