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/monitoring/logstash_plugin.py

@@ -28,30 +28,22 @@ options:
     state:
         description:
             - Apply plugin state.
-        required: False
         choices: ["present", "absent"]
         default: present
     plugin_bin:
         description:
             - Specify logstash-plugin to use for plugin management.
-        required: False
         default: /usr/share/logstash/bin/logstash-plugin
     proxy_host:
         description:
             - Proxy host to use during plugin installation.
-        required: False
-        default: None
     proxy_port:
         description:
             - Proxy port to use during plugin installation.
-        required: False
-        default: None
     version:
         description:
             - Specify plugin Version of the plugin to install.
               If plugin exists with previous version, it will NOT be updated.
-        required: False
-        default: None
 '''
 
 EXAMPLES = '''