Enforce ruff docstring validation and fix issues (#1868)

* Apply ruff

* Fix first docstrings

* Additional docstring fixes

* Improve AGENTS.md

* Enhance documentation across the pyoverkiz package

- Added module-level docstrings to various files including enums, models, and utilities to improve clarity and understanding of their purpose.
- Updated existing classes and methods with detailed docstrings to describe their functionality and usage.
- Improved test files with descriptive docstrings to clarify the purpose of each test case.
- Refactored some code for better readability and maintainability.

* Revert unneeded changes

Author: iMicknl

AGENTS.md

@@ -91,18 +91,6 @@ Always use full type annotations, generics, and other modern practices.
 - For longer tests put them in a file like `tests/test_somename.py` in the `tests/`
   directory (or `tests/module_name/test_somename.py` file for a submodule).
 
-- For simple tests, prefer inline functions in the original code file below a `## Tests`
-  comment. This keeps the tests easy to maintain and close to the code.
-  Inline tests should NOT import pytest or pytest fixtures as we do not want runtime
-  dependency on pytest.
-
-- DO NOT write one-off test code in extra files that are throwaway.
-
-- DO NOT put `if __name__ == "__main__":` just for quick testing.
-  Instead use the inline function tests and run them with `uv run pytest`.
-
-- You can run such individual tests with `uv run pytest -s src/.../path/to/test`
-
 - Don’t add docs to assertions unless it’s not obvious what they’re checking - the
   assertion appears in the stack trace.
   Do NOT write `assert x == 5, "x should be 5"`. Do NOT write `assert x == 5 # Check if
@@ -165,6 +153,8 @@ Always use full type annotations, generics, and other modern practices.
 
 ## Guidelines for Docstrings
 
+- Every method (or function) should have a docstring.
+
 - Here is an example of the correct style for docstrings:
   ```python
   def check_if_url(

pyoverkiz/__init__.py

@@ -0,0 +1,5 @@
+"""Async wrapper for the Overkiz (TaHoma) API.
+
+This package provides models, enums and a client to communicate with the
+Overkiz cloud and local gateway APIs.
+"""