Update CONTRIBUTING.md

Author: aromanielloNTIA

CONTRIBUTING.md

@@ -1,4 +1,4 @@
-# NTIA/ITS Propagation Library Contribution Guide - Python
+# NTIA/ITS Propagation Library Contribution Guide
 
 Thank you for your interest in contributing to this open source software. On this
 page you will get an overview of the contribution workflow from opening an issue,
@@ -210,8 +210,58 @@ double doubleTheInput(double x)
 
 ### Python Wrappers
 
+The Python wrapper code is documented in the [Sphinx](https://sphinx-rtd-tutorial.readthedocs.io/en/latest/docstrings.html)
+format. It is recommended to include docstrings for all primary functions, classes,
+or structures provided by the Python wrapper. Further, function signatures should
+include [type annotation](https://docs.python.org/3/library/typing.html) for inputs
+and returned values. Inline or other comments should be included to explain other
+variables or functionalities of the code. Below is an example showing the recommended
+documentation format.
 
+```python
+
+CONSTANT_EXPOSED_BY_MODULE = 42  # A brief comment could explain what this is
+
+def double_the_input(x: float) -> float:
+  """This is a brief description of the function.
+
+  This is an optional, longer description of the function.
+  It can span multiple lines.
+
+  :param x: The input value, and its expected units.
+  :return: The result y = 2*x
+  """
+  return 2 * x
+```
 
 ### C#/.NET Wrappers
 
-### MATLAB Wrappers
+In C#/.NET, documentation comments are written in XML format and are used to
+generate documentation through tools like Visual Studio. Use `<summary>` tags to
+provide brief descriptions of classes, constants, functions, etc. Functions should
+include `<param>` and `<returns>` elements for all inputs and outputs. An example
+of this documentation style is shown below.
+
+```csharp
+/// <summary>
+/// Represents a class that contains constants and methods related to calculations.
+/// </summary>
+public class CalculationUtils
+{
+    /// <summary>
+    /// A constant value exposed by the module.
+    /// </summary>
+    public const int CONSTANT_EXPOSED_BY_MODULE = 42;
+
+    /// <summary>
+    /// Doubles the input value.
+    /// </summary>
+    /// <param name="x">The input value to be doubled.</param>
+    /// <returns>The doubled value of the input.</returns>
+    public double DoubleTheInput(double x)
+    {
+        // Brief comment explaining what this function does.
+        return 2 * x;
+    }
+}
+```