Add style guide to contributing.md

CONTRIBUTING.md

@@ -1,6 +1,6 @@
-# Contributing
+# Contributing guidelines
 
-Contributions are welcome, and they are greatly appreciated! Every little bit helps, and credit will always be given.
+We welcome any kind of contribution to our software, from simple comment or question to a full fledged [pull request](https://help.github.com/articles/about-pull-requests/). Please read and follow our [Code of Conduct](CODE_OF_CONDUCT.md).
 
 ## Types of Contributions
 
@@ -76,6 +76,44 @@ Before you submit a pull request, ensure it meets these guidelines:
 2. If the pull request adds functionality, the documentation should be updated accordingly.
 3. The pull request should work for Python's currently supported versions and major operating systems.
 
+## Code Style Guide
+
+Please follow the coding standards and conventions outlined below when contributing to this project.
+
+1. **Use PEP 8 for Python code**: We follow the [PEP 8](https://www.python.org/dev/peps/pep-0008/) style guide for Python code. You can use tools like `black` to help enforce this.
+
+2. **Naming Conventions**:
+   * Function names: `snake_case`.
+   * Class names: `PascalCase`.
+   * Constants: `UPPER_CASE_WITH_UNDERSCORES`.
+
+3. **Docstrings**: All public methods, functions, and classes should have clear and complete docstrings. We use the [NumPy docstring style guide](https://numpydoc.readthedocs.io/en/latest/format.html) for consistency. Here is an example:
+
+    ```python
+    def my_function(param1: int, param2: str) -> None:
+        """
+        Brief summary of the function.
+
+        Parameters
+        ----------
+        param1 : int
+            Description of `param1`.
+        param2 : str
+            Description of `param2`.
+
+        Returns
+        -------
+        None
+        """
+        print(f"{param1}, {param2}")
+    ```
+
+4. **Type Annotations**: We use [PEP 484](https://www.python.org/dev/peps/pep-0484/) type hints throughout the codebase. Please ensure that all functions and methods are properly annotated.
+
+5. **Testing**: Ensure that your code is covered by unit tests. We use `pytest` for testing. Add new tests for any added functionality.
+
+We appreciate your contributions and adherence to the style guide. This helps maintain the quality and readability of the codebase.
+
 ## Code of Conduct
 
 Please note that the `tsdf` project is released with a Code of Conduct. By contributing to this project, you agree to abide by its terms.