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/cloud/amazon/ec2_vpc_igw_facts.py

@@ -25,13 +25,9 @@ options:
     description:
       - A dict of filters to apply. Each dict item consists of a filter key and a filter value.
         See U(http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeInternetGateways.html) for possible filters.
-    required: false
-    default: null
   internet_gateway_ids:
     description:
       - Get details of specific Internet Gateway ID. Provide this value as a list.
-    required: false
-    default: None
 extends_documentation_fragment:
     - aws
     - ec2