See Changelog.

• Breaking Change: alias precedence logic changed so aliases on a field always take priority over an alias from alias_generator to avoid buggy/unexpected behaviour, see here for details, #1178 by @samuelcolvin
• Add support for unicode and punycode in TLDs, #1182 by @jamescurtin
• Fix cls argument in validators during assignment, #1172 by @samuelcolvin
• completing Luhn algorithm for PaymentCardNumber, #1166 by @cuencandres
• add support for generics that implement __get_validators__ like a custom data type, #1159 by @tiangolo
• add support for infinite generators with Iterable, #1152 by @tiangolo
• fix url_regex to accept schemas with +, - and . after the first character, #1142 by @samuelcolvin
• move version_info() to version.py, suggest its use in issues, #1138 by @samuelcolvin
• Improve pydantic import time by roughly 50% by deferring some module loading and regex compilation, #1127 by @samuelcolvin
• Fix EmailStr and NameEmail to accept instances of themselves in cython, #1126 by @koxudaxi
• Pass model class to the Config.schema_extra callable, #1125 by @therefromhere
• Fix regex for username and password in URLs, #1115 by @samuelcolvin
• Add support for nested generic models, #1104 by @dmontagu
• add __all__ to __init__.py to prevent "implicit reexport" errors from mypy, #1072 by @samuelcolvin
• Add support for using "dotenv" files with BaseSettings, #1011 by @acnebs