docs: fix (#25)

Signed-off-by: nstarman <nstarman@users.noreply.github.com>

README.md

@@ -231,12 +231,12 @@ few useful converter functions. If you need more, check out `attrs`!
 
 ```python
 from attrs import define, field
-from dataclassish.converters import optional, ifnotisinstance
+from dataclassish.converters import Optional, Unless
 
 
 @define
 class Class1:
-    attr: int | None = field(default=None, converter=optional(int))
+    attr: int | None = field(default=None, converter=Optional(int))
 
 
 obj = Class1()
@@ -250,7 +250,7 @@ print(obj.attr)
 
 @define
 class Class2:
-    attr: float | int = field(converter=ifnotisinstance((int,), converter=float))
+    attr: float | int = field(converter=Unless(int, converter=float))
 
 
 obj = Class2(1)

src/dataclassish/converters.py

@@ -5,19 +5,6 @@
 includes: ``attrs`` and ``equinox``. This module provides a few useful converter
 functions. If you need more, check out ``attrs``!
 
-A quick rant of why rejecting PEP 712 was a bad idea. A core design guideline
-for Python is Postel's Law: "be conservative in what you send, be liberal in
-what you accept" (https://en.wikipedia.org/wiki/Robustness_principle). Currently
-dataclasses are conservative in what they "send" (i.e., the types of their
-attributes when accessed from an instance of a dataclass). The problem is that
-without converters dataclasses are ALSO conservative in what they "accept" (how
-they can be initialized), since they require that the types of the attributes
-match the types of the fields. The onus of data structuring is forced on the
-user. This is a violation of Postel's Law. Without PEP 712's converter support
-the only way to be liberal in the what dataclasses accept is to write a custom
-``__init__`` method, in which case why are we even using a dataclass?! The
-rejection of PEP 712 directly contradicts a core design principle of Python.
-
 """
 # ruff:noqa: N801
 # pylint: disable=C0103