title: Completion Suggester in elastic search does not return results
body: <p>I'm having difficulties to make the Completion Suggester work in my code.</p>
  
  <p>I'm trying to make an autocomplete component that will search previously run queries. I want to use the Completion Suggester.  </p>
  
  <p>I have the following mapping:</p>
  
  <pre><code>{
    "liferay-20116": {
      "mappings": {
        "querySuggestion": {      
          "properties": {
            "companyId": {
              "type": "string",
              "index": "not_analyzed",
              "store": true
            },
            "keywordSearch_en": {
              "type": "string",
              "fields": {
                "ngram": {
                  "type": "string",
                  "analyzer": "gsearch_shingle_analyzer",
                  "search_analyzer": "standard"
                },
                "suggest": {
                  "type": "completion",
                  "analyzer": "simple",
                  "payloads": false,
                  "preserve_separators": true,
                  "preserve_position_increments": true,
                  "max_input_length": 50,
                  "context": {
                    "company": {
                      "type": "category",
                      "path": "companyId",
                      "default": [
                        "20116"
                      ]
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
  </code></pre>
  
  <p>I want to run a suggestion on the <em>keywordSearch_en</em> field. I tried </p>
  
  <pre><code>POST liferay-20116/_suggest 
  {
    "my-suggester": {
      "text": "service",
      "completion": {
        "field": "suggest"
      }
    }
  }
  </code></pre>
  
  <p>I'm getting only this error message: "Field [suggest] is not a completion suggest field".</p>
  
  <p>What am I doing wrong? </p>