Python: further improvements to checks and docs in dev_setup (microsoft#6445)

### Motivation and Context

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Added a section on documentation to the DEV_SETUP
Added a check for the copyright row to pre-commit
Closes microsoft#5629

### Description

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### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [x] The code builds clean without any errors or warnings
- [x] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [x] All unit tests pass, and I have added new tests where possible
- [x] I didn't break anyone 😄

Author: eavanvalkenburg

python/DEV_SETUP.md

@@ -155,6 +155,57 @@ It's important to note that most of this library is written with asynchronous in
 developer should always assume everything is asynchronous. One can use the function signature
 with either `async def` or `def` to understand if something is asynchronous or not.
 
+### Documentation
+
+Each file should have a single first line containing: # Copyright (c) Microsoft. All rights reserved.
+
+We follow the [Google Docstring](https://github.com/google/styleguide/blob/gh-pages/pyguide.md#383-functions-and-methods) style guide for functions and methods.
+They are currently not checked for private functions (functions starting with '_').
+
+They should contain:
+- Single line explaining what the function does, ending with a period.
+- If necessary to further explain the logic a newline follows the first line and then the explanation is given.
+- The following three sections are optional, and if used should be separated by a single empty line.
+- Arguments are then specified after a header called `Args:`, with each argument being specified in the following format:
+    - `arg_name` (`arg_type`): Explanation of the argument, arg_type is optional, as long as you are consistent.
+    - if a longer explanation is needed for a argument, it should be placed on the next line, indented by 4 spaces.
+    - Default values do not have to be specified, they will be pulled from the definition.
+- Returns are specified after a header called `Returns:` or `Yields:`, with the return type and explanation of the return value.
+- Finally, a header for exceptions can be added, called `Raises:`, with each exception being specified in the following format:
+    - `ExceptionType`: Explanation of the exception.
+    - if a longer explanation is needed for a exception, it should be placed on the next line, indented by 4 spaces.
+
+Putting them all together, gives you at minimum this:
+
+```python
+def equal(arg1: str, arg2: str) -> bool:
+    """Compares two strings and returns True if they are the same."""
+    ...
+```
+Or a complete version of this:
+
+```python
+def equal(arg1: str, arg2: str) -> bool:
+    """Compares two strings and returns True if they are the same.
+
+    Here is extra explanation of the logic involved.
+
+    Args:
+        arg1 (str): The first string to compare.
+        arg2 (str): The second string to compare.
+            This string requires extra explanation.
+
+    Returns:
+        bool: True if the strings are the same, False otherwise.
+
+    Raises:
+        ValueError: If one of the strings is empty.
+    """
+    ...
+```
+
+If in doubt, use the link above to read much more considerations of what to do and when, or use common sense.
+
 ## Pydantic and Serialization
 
 [Pydantic Documentation](https://docs.pydantic.dev/1.10/)

python/pyproject.toml

@@ -127,18 +127,24 @@ target-version = "py310"
 include = ["*.py", "*.pyi", "**/pyproject.toml", "*.ipynb"]
 
 [tool.ruff.lint]
-select = ["D", "E", "F", "I"]
-ignore = ["D100", "D101", "D104"]
+preview = true
+select = ["D", "E", "F", "I", "CPY", "ISC", "INP", "RSE102", "RET", "SIM", "TD", "FIX", "ERA001", "RUF"]
+ignore = ["D100", "D101", "D104", "TD003", "FIX002"]
 
 [tool.ruff.lint.pydocstyle]
 convention = "google"
 
 [tool.ruff.lint.per-file-ignores]
-# Ignore all directories named `tests`.
-"tests/**" = ["D"]
-"samples/**" = ["D"]
+# Ignore all directories named `tests` and `samples`.
+"tests/**" = ["D", "INP", "TD", "ERA001", "RUF"]
+"samples/**" = ["D", "INP", "ERA001", "RUF"]
 # Ignore all files that end in `_test.py`.
 "*_test.py" = ["D"]
+"*.ipynb" = ["CPY", "E501"]
+
+[tool.ruff.lint.flake8-copyright]
+notice-rgx = "^# Copyright \\(c\\) Microsoft\\. All rights reserved\\."
+min-file-size = 1
 
 [tool.bandit]
 targets = ["python/semantic_kernel"]