Include documentation url inside JSON Schema

Adding a link to official documentation inside JSON Schema, so its
users, such ansible-lint can recommend it when validation fails.

Needed-By: ansible/ansible-lint#3684

ansible_rulebook/schema/ruleset_schema.json

@@ -1,6 +1,8 @@
 {
     "$schema": "http://json-schema.org/draft-07/schema#",
     "$id": "https://raw.githubusercontent.com/ansible/ansible-rulebook/main/ansible_rulebook/schema/ruleset_schema.json",
+    "title": "Ansible Rulebook",
+    "description": "See https://ansible.readthedocs.io/projects/rulebook/en/stable/rulebooks.html",
     "type": "array",
     "items": {
         "$ref": "#/$defs/ruleset"