Update unit testing docs (#55272)

* Updated links
* Updated indentation
* Fixed typos

Fixes: #55242

Signed-off-by: Abhijeet Kasurde <akasurde@redhat.com>

docs/docsite/rst/dev_guide/testing_units_modules.rst

@@ -190,8 +190,9 @@ above, either by throwing an exception or ensuring that they haven't been called
     class AnsibleExitJson(Exception):
         """Exception class to be raised by module.exit_json and caught by the test case"""
         pass
-    #you may also do the same to fail json
-    module=MagicMock()
+
+    # you may also do the same to fail json
+    module = MagicMock()
     module.exit_json.side_effect = AnsibleExitJson(Exception)
     with self.assertRaises(AnsibleExitJson) as result:
         return = my_module.test_this_function(module, argument)
@@ -300,7 +301,7 @@ variable is set it will be treated as if the input came on ``STDIN`` to the modu
         args = json.dumps({'ANSIBLE_MODULE_ARGS': args})
         basic._ANSIBLE_ARGS = to_bytes(args)
 
-    simply call that function before setting up your module
+simply call that function before setting up your module::
 
     def test_already_registered(self):
         set_module_args({
@@ -334,6 +335,7 @@ testing for the correct exception::
             'username': 'user',
             'password': 'pass',
         })
+
         with self.assertRaises(AnsibleExitJson) as result:
             my_module.main()
 
@@ -349,7 +351,7 @@ the arguments as above, set up the appropriate exit exception and then run the m
 
     # This test is based around pytest's features for individual test functions
     import pytest
-    import ansible.modules.module.group.my_modulle as my_module
+    import ansible.modules.module.group.my_module as my_module
 
     def test_main_function(monkeypatch):
         monkeypatch.setattr(my_module.AnsibleModule, "exit_json", fake_exit_json)
@@ -559,8 +561,8 @@ the code in Ansible to trigger that failure.
        General advice on testing Python code
    `Uncle Bob's many videos on YouTube <https://www.youtube.com/watch?v=QedpQjxBPMA&list=PLlu0CT-JnSasQzGrGzddSczJQQU7295D2>`_
        Unit testing is a part of the of various philosophies of software development, including
-       Extreme Programming (XP), Clean Coding.  Uncle Bob talks through how to benfit from this
-   `"Why Most Unit Testing is Waste" https://rbcs-us.com/documents/Why-Most-Unit-Testing-is-Waste.pdf`
+       Extreme Programming (XP), Clean Coding.  Uncle Bob talks through how to benefit from this
+   `"Why Most Unit Testing is Waste" <https://rbcs-us.com/documents/Why-Most-Unit-Testing-is-Waste.pdf>`_
        An article warning against the costs of unit testing
-   `'A Response to "Why Most Unit Testing is Waste"' https://henrikwarne.com/2014/09/04/a-response-to-why-most-unit-testing-is-waste/`
+   `'A Response to "Why Most Unit Testing is Waste"' <https://henrikwarne.com/2014/09/04/a-response-to-why-most-unit-testing-is-waste/>`_
        An response pointing to how to maintain the value of unit tests