Refer the mypy-plugin extras in the docs

Author: zhukovgreen

README.md

@@ -32,9 +32,14 @@ Smart, pythonic, ad-hoc, typed polymorphism for Python.
 pip install classes
 ```
 
-You also need to [configure](https://classes.readthedocs.io/en/latest/pages/container.html#type-safety)
+You may also need to [configure](https://classes.readthedocs.io/en/latest/pages/container.html#type-safety)
 `mypy` correctly and install our plugin:
 
+```bash
+pip install classes[mypy-plugin]
+```
+and
+
 ```ini
 # In setup.cfg or mypy.ini:
 [mypy]

pyproject.toml

@@ -46,7 +46,7 @@ classifiers = [
 [tool.poetry.dependencies]
 python = "^3.7"
 typing_extensions = ">=3.10,<5.0"
-mypy = { version = "^0.942", optional = true }
+mypy = { version = "^1.2.0", optional = true }
 
 [tool.poetry.dev-dependencies]
 mypy = "^0.942"