title: Adding Column Description to BigQuery schema definition
body: <p>Is it possible to specify comments in the schema definition of a BigQuery table via the API?</p>
  
  <p>I use the following schema when creating a BigQuery table via the Hadoop connector</p>
  
  <pre><code>[{"name" : "event_id", "type" : "integer"},{ "name" : "categorization" , "type" : "string" }]
  </code></pre>
  
  <p>And I want something like</p>
  
  <pre><code>[{"name" : "event_id", "type" : "integer", "description" : "The event identifier"},{ "name" : "categorization" , "type" : "string" }]
  </code></pre>
  
  <p>EDIT: I've just tried this with the spark connector but it doesn't work. The descriptions are still empty</p>
  
  <pre><code>BigQueryConfiguration.configureBigQueryOutput(
        bqConfiguration, projectId, bqDatasetId, bqTable, schema)
      bqConfiguration.set(
        "mapreduce.job.outputformat.class",
        classOf[BigQueryOutputFormat[_,_]].getName)
  
      new JavaPairRDD(rdd.map((null, _))).saveAsNewAPIHadoopDataset(bqConfiguration)
    }
  </code></pre>
  
  <p>DOUBLE EDIT: Added some code for context</p>