test(cli): add tests for the CLI

tests/unit/cli/python_project/expected/pkg/module.md

@@ -0,0 +1,20 @@
+# Module `pkg.module`
+
+## Function `f`
+
+Does something.
+
+
+### Parameters
+
+| Parameter | Type | Kind | Default value | Description |
+| --- | --- | --- | --- | --- |
+| `a` | `int` | normal | `42` | A parameter. |
+
+<details><summary><h3 style="display:inline">Docstring</h3></summary>Does something.
+
+:param a: A parameter.
+:type a: int
+
+:return: A string.
+:rtype: str</details>

tests/unit/cli/python_project/project/src/pkg/module.py

@@ -0,0 +1,11 @@
+def f(a: int = 42) -> str:
+    '''
+    Does something.
+
+    :param a: A parameter.
+    :type a: int
+
+    :return: A string.
+    :rtype: str
+    '''
+    ...