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/openstack/os_security_group_rule.py

@@ -31,26 +31,19 @@ options:
       description:
         - IP protocols TCP UDP ICMP 112 (VRRP)
       choices: ['tcp', 'udp', 'icmp', '112', None]
-      default: None
    port_range_min:
       description:
         - Starting port
-      required: false
-      default: None
    port_range_max:
       description:
         - Ending port
-      required: false
-      default: None
    remote_ip_prefix:
       description:
         - Source IP address(es) in CIDR notation (exclusive with remote_group)
-      required: false
    remote_group:
       description:
         - Name or ID of the Security group to link (exclusive with
           remote_ip_prefix)
-      required: false
    ethertype:
       description:
         - Must be IPv4 or IPv6, and addresses represented in CIDR must
@@ -71,7 +64,6 @@ options:
    availability_zone:
      description:
        - Ignored. Present for backwards compatibility
-     required: false
 requirements: ["shade"]
 '''