docs: document tests

tests/test_basic.py

@@ -1,3 +1,5 @@
+"""Basics tests for the slope function."""
+
 import unittest
 
 import numpy as np
@@ -7,7 +9,38 @@
 
 
 class TestBasicUse(unittest.TestCase):
+    """
+    A class used to test the basic use of the Slope model.
+
+    ...
+
+    Attributes
+    ----------
+    None
+
+    Methods
+    -------
+    test_simple_problem():
+        Tests a simple problem using the Slope model.
+    """
+
     def test_simple_problem(self):
+        """
+        Tests a simple problem using the Slope model.
+
+        This method generates a random dataset using the numpy random module,
+        creates a Slope model with specific parameters, fits the model to the
+        generated data, and then checks if the model's coefficients are almost
+        equal to the expected coefficients.
+
+        Parameters
+        ----------
+        None
+
+        Returns
+        -------
+        None
+        """
         n = 10
         p = 3
         rng = default_rng(4)