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/source_control/github_deploy_key.py

@@ -25,63 +25,48 @@ options:
     description:
       - The name of the individual account or organization that owns the GitHub repository.
     required: true
-    default: null
     aliases: [ 'account', 'organization' ]
   repo:
     description:
       - The name of the GitHub repository.
     required: true
-    default: null
     aliases: [ 'repository' ]
   name:
     description:
       - The name for the deploy key.
     required: true
-    default: null
     aliases: [ 'title', 'label' ]
   key:
     description:
       - The SSH public key to add to the repository as a deploy key.
     required: true
-    default: null
   read_only:
     description:
       - If C(true), the deploy key will only be able to read repository contents. Otherwise, the deploy key will be able to read and write.
-    required: false
     type: bool
-    default: yes
+    default: 'yes'
   state:
     description:
       - The state of the deploy key.
-    required: false
     default: "present"
     choices: [ "present", "absent" ]
   force:
     description:
       - If C(true), forcefully adds the deploy key by deleting any existing deploy key with the same public key or title.
-    required: false
-    default: no
     type: bool
+    default: 'no'
   username:
     description:
       - The username to authenticate with.
-    required: false
-    default: null
   password:
     description:
       - The password to authenticate with. A personal access token can be used here in place of a password.
-    required: false
-    default: null
   token:
     description:
       - The OAuth2 token or personal access token to authenticate with. Mutually exclusive with I(password).
-    required: false
-    default: null
   otp:
     description:
       - The 6 digit One Time Password for 2-Factor Authentication. Required together with I(username) and I(password).
-    required: false
-    default: null
     aliases: ['2fa_token']
 requirements:
    - python-requests