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/system/authorized_key.py

@@ -32,7 +32,6 @@ options:
   path:
     description:
       - Alternate path to the authorized_keys file
-    required: false
     default: "(homedir)+/.ssh/authorized_keys"
     version_added: "1.2"
   manage_dir:
@@ -43,21 +42,17 @@ options:
         set C(manage_dir=no) if you are using an alternate directory for
         authorized_keys, as set with C(path), since you could lock yourself out of
         SSH access. See the example below.
-    required: false
-    choices: [ "yes", "no" ]
-    default: "yes"
+    type: bool
+    default: 'yes'
     version_added: "1.2"
   state:
     description:
       - Whether the given key (with the given key_options) should or should not be in the file
-    required: false
     choices: [ "present", "absent" ]
     default: "present"
   key_options:
     description:
       - A string of ssh key options to be prepended to the key in the authorized_keys file
-    required: false
-    default: null
     version_added: "1.4"
   exclusive:
     description:
@@ -66,26 +61,22 @@ options:
       - This option is not loop aware, so if you use C(with_) , it will be exclusive per iteration
         of the loop, if you want multiple keys in the file you need to pass them all to C(key) in a
         single batch as mentioned above.
-    required: false
-    choices: [ "yes", "no" ]
-    default: "no"
+    type: bool
+    default: 'no'
     version_added: "1.9"
   validate_certs:
     description:
       - This only applies if using a https url as the source of the keys. If set to C(no), the SSL certificates will not be validated.
       - This should only set to C(no) used on personally controlled sites using self-signed certificates as it avoids verifying the source site.
       - Prior to 2.1 the code worked as if this was set to C(yes).
-    required: false
-    default: "yes"
-    choices: ["yes", "no"]
+    type: bool
+    default: 'yes'
     version_added: "2.1"
   comment:
     description:
       - Change the comment on the public key. Rewriting the comment is useful in
         cases such as fetching it from GitHub or GitLab.
       - If no comment is specified, the existing comment will be kept.
-    required: false
-    default: None
     version_added: "2.4"
 author: "Ansible Core Team"
 '''