message: Correct the definition of WebApiSkill
diff: }
  },
  "required": [
  - "uri",
  - "httpHeaders",
  - "httpMethod"
  + "uri"
  ],
  "externalDocs": {
  - "url": "https://docs.microsoft.com/azure/search/cognitive-search-custom-skill-interface"
  + "url": "https://docs.microsoft.com/azure/search/cognitive-search-custom-skill-web-api"
  },
  "description": "A skill that can call a Web API endpoint, allowing you to extend a skillset by having it call your custom code."
  },
  "WebApiHttpHeaders": {
  - "properties": {
  - "headers": {
  "type": "object",
  "additionalProperties": {
  "type": "string"
  },
  "description": "A dictionary of http request headers."
  - }
  - }
  },
  "SkillsetListResult": {
  "properties": {
  