Clean up module documentation (#36909)

* Clean up module documentation

This PR includes:
- Removal of `default: None` (and variations)
- Removal of `required: false`
- Fixing booleans and `type: bool` where required

* Fix remaining (new) validation issues

lib/ansible/modules/utilities/logic/include_role.py

@@ -33,28 +33,25 @@ options:
   tasks_from:
     description:
       - File to load from a role's C(tasks/) directory.
-    required: False
     default: main
   vars_from:
     description:
       - File to load from a role's C(vars/) directory.
-    required: False
     default: main
   defaults_from:
     description:
       - File to load from a role's C(defaults/) directory.
-    required: False
     default: main
   allow_duplicates:
     description:
       - Overrides the role's metadata setting to allow using a role more than once with the same parameters.
-    required: False
-    default: True
+    type: bool
+    default: 'yes'
   private:
     description:
-      - If C(True) the variables from C(defaults/) and C(vars/) in a role will not be made available to the rest of the
+      - If C(yes) the variables from C(defaults/) and C(vars/) in a role will not be made available to the rest of the
         play.
-    default: None
+    type: bool
 notes:
   - Handlers are made available to the whole play.
   - Before Ansible 2.4, as with C(include), this task could be static or dynamic, If static, it implied that it won't