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/net_tools/nios/nios_zone.py

@@ -29,7 +29,6 @@ options:
       - Specifies the qualified domain name to either add or remove from
         the NIOS instance based on the configured C(state) value.
     required: true
-    default: null
     aliases:
       - name
   view:
@@ -44,17 +43,14 @@ options:
   grid_primary:
     description:
       - Configures the grid primary servers for this zone.
-    required: false
     suboptions:
       name:
         description:
           - The name of the grid primary server
         required: true
-        default: null
   grid_secondaries:
     description:
       - Configures the grid secondary servers for this zone.
-    required: false
     suboptions:
       name:
         description:
@@ -65,20 +61,17 @@ options:
       - Allows for the configuration of Extensible Attributes on the
         instance of the object.  This argument accepts a set of key / value
         pairs for configuration.
-    required: false
   comment:
     description:
       - Configures a text string comment to be associated with the instance
         of this object.  The provided text string will be configured on the
         object instance.
-    required: false
   state:
     description:
       - Configures the intended state of the instance of the object on
         the NIOS server.  When this value is set to C(present), the object
         is configured on the device and when this value is set to C(absent)
         the value is removed (if necessary) from the device.
-    required: false
     default: present
     choices:
       - present